Catalyst / Bypass

Catalytic converter repair flange

Fits:
Porsche 964 (911) C2 1989-93
Porsche 964 (911) C4 1989-93
Porsche 964 (911) RS 3.6L 1991-93
Porsche 964 (911) RS 3.8L 1991-93

Ninemeister Converter Repair Flange 

Over time, age, heat cycles, and corrosion take their toll on Porsche exhaust systems. A common weak point is the catalytic converter flange, which can corrode and eventually disintegrate. When this happens, it compromises the seal in your exhaust system, leading to exhaust leaks, loss of performance, and increased noise.

The Ninemeister repair flange is a high-quality replacement solution designed specifically to restore your Porsche’s exhaust integrity.

Key Features

• Direct Repair Solution – allows you to remove the corroded flange and re-weld this precision-machined replacement in place.
  
• Durable Construction – built to withstand the extreme heat and corrosive conditions of Porsche exhaust systems.
  
• Restores Exhaust Sealing – eliminates leaks, restores back pressure, and ensures smooth engine performance.
  
• Cost-Effective Repair – no need to replace the entire catalytic converter when only the flange is damaged.
  
• Tailored Fitment – engineered to match Porsche specifications for proper alignment and fit.

Why Replace a Corroded Converter Flange?

• Eliminate Exhaust Leaks – prevent harmful gases from escaping and affecting cabin safety.
  
• Restore Performance – exhaust leaks reduce back pressure, causing poor throttle response and reduced efficiency.
  
• Prevent Further Damage – corrosion at the flange can spread, leading to costly catalytic converter or exhaust system replacements.
  
• Long-Term Reliability – a fresh flange ensures your exhaust remains structurally sound for years to come.

The Ninemeister catalytic converter repair flange provides a reliable, cost-effective fix for corroded catalytic converter flanges, helping you keep your Porsche exhaust system safe, efficient, and true to factory performance.

Section of diagram ref no 1

Related reference numbers
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9M96411104205

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Exhaust Catalytic Converter Bypass Pipes

DesignTek stainless steel catalyst by-pass produces more air flow which in turn produces more power. Designed to give a deeper more sporter sound.

This product comes with the hole to re-fit the lambda sensor.

Fits:
Porsche 964 C2 / C4 1989-94

Please note: These sport cats will make your car sound louder than with stock cats. If you have ,or intend to install sport silencers, you may find the car is a bit loo loud. We recommend to use one sport exhaust component if you are concerned about decibel levels.

Design 911 Recommends this product best value and best quality

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

3606209641

The product you are viewing cross references to these numbers

Exhaust Catalytic Converter Pipes 100 Cell

DesignTek stainless steel sports 100 cell catalyst, with German hi-flow catalyst. Produces more air flow which in turn produces more power. Designed to give a deeper more sporter sound.

This product comes with the hole to re-fit the lambda sensor.

Fits:
Porsche 964 C2 / C4 1989-94

Please note: These sport cats will make your car sound louder than with stock cats. If you have ,or intend to install sport silencers, you may find the car is a bit loo loud. We recommend to use one sport exhaust component if you are concerned about decibel levels.

Design 911 Recommends this product best value and best quality

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

3606109641

The product you are viewing cross references to these numbers

Sports Catalytic Converter with catalytic ceramic insert, 100 cell. With Lambda sensor hole and plug. Polished stainless steel.

Fits:
Porsche 964 C2 / C4 1990-94

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

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1620301400

The product you are viewing cross references to these numbers

Sports Catalytic Converter without catalytic ceramic insert. With Lambda sensor hole and plug. Polished stainless steel. This is a Cat bypass product.

Fits:
Porsche 964 C2 / C4 1990-94

Please note: These sport cats will make your car sound louder than with stock cats. If you have ,or intend to install sport silencers, you may find the car is a bit loo loud. We recommend to use one sport exhaust component if you are concerned about decibel levels.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96421100391

The product you are viewing cross references to these numbers

Fabspeed European Pre-Muffler Pipe.
The Fabspeed Porsche 964 Carrera European Pre-Muffler / Cat Bypass Pipe is a performance exhaust component designed to replace the factory catalytic converter with a freer-flowing exhaust section for competition and off-road applications.

Fits:

• Porsche 964 (911) C2 1989-94
• Porsche 964 (911) C4 1989-94 

Inspired by the European-style pre-muffler configuration, the pipe reduces the restriction associated with the original catalytic converter while incorporating an internal resonator to help shape the exhaust note.

Manufactured from T304L stainless steel, this lightweight exhaust upgrade is designed to improve exhaust flow, enhance throttle response and produce a stronger, more sporting air-cooled flat-six exhaust character.

Because this component removes the catalytic converter, it is intended for competition and off-road use only where legally permitted.

What This Product Does:
The standard catalytic converter processes exhaust gases to reduce harmful emissions before they leave the vehicle.

For competition applications, the Fabspeed European Pre-Muffler replaces this catalytic converter with a much freer-flowing exhaust path.

Removing the catalyst restriction allows exhaust gases to pass through the system more easily.

The pre-muffler is designed to:

• Reduce exhaust restriction
• Improve exhaust-gas flow
• Improve engine breathing
• Enhance throttle response
• Support improved performance
• Reduce exhaust-system weight
• Produce a stronger exhaust note
• Provide a European-style pre-muffler configuration

European Pre-Muffler Design:

• Rather than using a simple straight catalyst-delete pipe, Fabspeed incorporates an internal resonator into the system.
• This provides a freer-flowing exhaust path while helping control and shape the sound produced by the air-cooled flat-six engine.
• The result is intended to provide a more sporting exhaust character without simply functioning as an unrestricted straight pipe.

Why Upgrading Matters:
The Fabspeed European Pre-Muffler is primarily a performance modification, rather than a routine replacement for a failed catalytic converter.

For a suitable competition or off-road Porsche 964, reasons for upgrading can include:

• Reduced exhaust restriction
• Improved exhaust flow
• Improved throttle response
• Reduced exhaust-system weight
• More pronounced flat-six sound
• European-style pre-muffler configuration
• T304L stainless-steel construction
• Direct bolt-on installation

It can also complement other performance exhaust modifications fitted to the vehicle.

Related reference numbers
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FSPOR964CB

The product you are viewing cross references to these numbers

Fabspeed HJS High flow Sport Cat. 

The Fabspeed HJS High-Flow Sport Catalytic Converter is a performance exhaust upgrade for the Porsche 964 Turbo, C2 Turbo designed to replace an ageing, restrictive or previously removed original catalytic converter.

Fits:

• Porsche 964 (911) TURBO 3.3L 1990-94
• Porsche 964 (911) TURBO 3.6L 1990-94

At the heart of the system is a 200-cell HJS high-flow catalytic converter, engineered to reduce exhaust emissions while providing substantially less restriction than older factory catalyst technology. The system is manufactured using 14–16 gauge CNC mandrel-bent T304L stainless steel, providing a durable, corrosion-resistant exhaust path designed for improved gas flow.

By reducing exhaust restriction after the turbocharger, the sport catalyst can help the turbocharged flat-six breathe more efficiently, supporting improved throttle response and performance while retaining catalytic exhaust-gas treatment.

What This Product Does:

• Replaces the original catalytic converter section.
• Converts harmful exhaust pollutants before gases leave the exhaust system.
• Provides significantly greater exhaust flow than an ageing or restrictive factory catalyst.
• Reduces exhaust backpressure after the turbocharger.
• Helps improve throttle response.
• Can support improved turbo response and engine performance.
• Provides a performance-oriented alternative to an original 1990s catalytic converter.
• Restores catalytic-converter functionality on vehicles where the original catalyst has previously been removed.
• Uses a high-flow 200-cell HJS catalyst rather than a conventional dense factory-style catalyst.
• Uses stainless-steel construction for corrosion resistance and durability.
• Retains catalytic treatment while offering flow characteristics closer to a less restrictive exhaust system.

Fabspeed states that its HJS high-flow catalysts can flow at more than 90% of the rate of a straight pipe in applicable installations while still providing catalytic exhaust-gas treatment.

Symptoms Of Wear Or Failure:
An original catalytic converter can deteriorate internally after decades of heat cycles, vibration and exposure to exhaust gases.

Possible symptoms include:

• Noticeable loss of engine power.
• Poor throttle response.
• Sluggish turbo response.
• Engine feeling restricted at higher RPM.
• Difficulty achieving full boost or performance.
• Excessive exhaust backpressure.
• Increased exhaust temperatures.
• Rattling noises from inside the catalytic converter.
• Metallic noises caused by a loose or broken catalyst core.
• Strong or unusual exhaust smells.
• Failed emissions testing.
• Increased exhaust emissions.
• Catalyst housing becoming excessively hot.
• Reduced fuel economy.
• Engine running poorly under load.
• Visible corrosion or damage to the original converter.
• Exhaust leaks around the converter or flanges.

A partially blocked catalyst may allow the engine to run reasonably well at low speed but restrict exhaust flow increasingly as engine speed and load rise.

Why Replacement Matters:
The catalytic converter sits directly in the exhaust path, so its internal condition has a major influence on both emissions performance and exhaust flow.

As the catalyst ages, the internal substrate can deteriorate, melt, become contaminated or break apart. A damaged catalyst may become increasingly restrictive, creating excessive exhaust backpressure.

On a turbocharged engine, restriction after the turbocharger is particularly undesirable because the turbocharger must push exhaust gases through the converter.

Replacing a worn or restrictive converter can help restore:

• Proper exhaust flow.
• Turbocharger response.
• Throttle response.
• Engine performance.
• Exhaust-gas treatment.
• Correct operating temperatures.
• Reliable exhaust-system operation.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

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FSPOR964TSC

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Fabspeed Muffler Bypass IMSA Zork Tube. 

The Fabspeed Porsche C2 Turbo / 965 / 964 Turbo Muffler Bypass IMSA Zork Tube is a competition-inspired performance exhaust upgrade designed for Porsche 911 Turbo models manufactured between 1990 and 1994.

Fits:

• Porsche 964 (911) TURBO 3.3L 1990-94
• Porsche 964 (911) TURBO 3.6L 1990-94

Developed by Fabspeed Motorsport, this high-flow exhaust component recreates the distinctive short exhaust outlet design associated with the legendary Porsche 934 IMSA and Le Mans racing cars of the late 1970s.

The IMSA Zork Tube replaces the original restrictive rear exhaust arrangement with a short, large-diameter outlet that directs exhaust gases away from the turbocharger with minimal downstream restriction.

Its design is intended to deliver maximum exhaust sound, improved turbocharger response and a dramatic motorsport-inspired driving experience.

Manufactured with 3.0-inch (76 mm) exhaust tubing, the Fabspeed Zork Tube features an integrated angle-cut outlet that can be adjusted to achieve the correct position beneath the rear bumper.

By reducing exhaust restrictions after the turbocharger, this system is designed to improve exhaust gas evacuation and allow the turbocharger to respond more freely.

Fabspeed advertises performance gains of up to 46 wheel horsepower and 65 lb-ft of torque, based on its published testing. Actual results depend on engine condition, vehicle specification, existing modifications and operating conditions.

One of the most distinctive features of this product is its sound. The Zork Tube creates an exceptionally loud, aggressive exhaust character, with pronounced turbocharger whistle, spool-up sounds, crackles, pops and exhaust burbles.

Unlike a conventional sports muffler, the IMSA Zork Tube prioritises exhaust flow and sound over noise reduction.

The direct-fit design uses four mounting nuts at the turbocharger connection and an adjustable slip-joint outlet, allowing straightforward installation on a compatible exhaust configuration.

The Fabspeed IMSA Zork Tube is ideally suited to Porsche 964 Turbo and 965 owners preparing vehicles for track days, motorsport events or dedicated competition use.

What This Product Does:
The Fabspeed IMSA Zork Tube provides a short, high-flow exhaust route from the turbocharger towards the rear of the vehicle.

Instead of passing exhaust gases through the standard rear muffler arrangement, the Zork Tube allows them to exit through a substantially less restrictive pipe.

Its key functions and benefits include:

• Reduced Exhaust Backpressure: Provides a freer-flowing outlet after the turbocharger.
• Improved Exhaust Gas Flow: Uses 3.0-inch (76 mm) tubing to support efficient exhaust evacuation.
• Enhanced Turbocharger Response: Reduced downstream restriction may help the turbocharger build boost more readily.
• Increased Performance Potential: Fabspeed advertises gains of up to 46 wheel horsepower and 65 lb-ft of torque.
• Aggressive Race-Inspired Sound: Produces an extremely loud exhaust note inspired by historic Porsche competition cars.
• Pronounced Turbo Whistle: Makes turbocharger spool-up and operating sounds considerably more noticeable.
• Exhaust Crackles and Pops: Allows more combustion-related exhaust sounds to be heard.
• Direct Exhaust Routing: Minimises the complexity and length of the downstream exhaust path.
• Reduced Exhaust System Weight: Eliminates heavier original exhaust components where replaced by the tube, although Fabspeed does not publish a confirmed weight-saving figure for this product.
• Adjustable Outlet Position: Features an angle-cut outlet with a slip-joint adjustment.
• Motorsport Appearance: Recreates the distinctive short exhaust arrangement associated with Porsche 934 IMSA race cars.
• Straightforward Installation: Designed to attach directly to the compatible turbocharger outlet arrangement.
• Reversible Modification: Allows original components to be retained and refitted when required.

Symptoms Of Wear Or Failure:
The Fabspeed IMSA Zork Tube is primarily a performance and motorsport upgrade, rather than a routine replacement for a worn exhaust component.

However, owners may consider replacing or refurbishing their original exhaust system when it shows signs of damage or deterioration.

• Older mufflers and exhaust pipes can develop corrosion following prolonged exposure to moisture, road salt and repeated temperature changes.
• Severe corrosion may weaken the exhaust housing, joints and mounting points.
• Cracked pipework, failed gaskets or damaged connections can allow exhaust gases to escape before reaching the intended outlet.
• Symptoms may include blowing noises, increased exhaust volume and visible soot around leaking joints.
• Internal baffles or other components inside an ageing muffler may become loose or damaged.
• This can produce metallic rattling, unusual vibrations or changes in exhaust sound.
• Damaged or obstructed exhaust components may restrict gas flow, increasing exhaust backpressure.
• Severe restriction can affect engine output and turbocharger operating conditions.
• A severely restricted exhaust system may contribute to slower boost response or reduced engine performance.
• However, these symptoms can also result from turbocharger wear, boost leaks, wastegate faults or other engine problems.
• Corroded fasteners, fractured brackets or deteriorated supports may allow unwanted exhaust movement.
• This can produce rattling, vibration or contact with surrounding bodywork.
• Impact damage, crushed sections or deformed pipework can compromise the structural condition of the original exhaust.
• Loose connections or failed supports may allow the exhaust system to move beyond its intended position.
• A leaking exhaust may allow fumes to escape near the engine compartment or vehicle body.
• Exhaust leaks should be investigated promptly because exhaust gases can contain dangerous carbon monoxide.
• Corrosion or deformation around flange connections may prevent the exhaust from sealing correctly.

Why Replacement / Upgrading Matters:

• Upgrading to the Fabspeed IMSA Zork Tube offers a distinctive motorsport-focused exhaust configuration for Porsche 964 Turbo and 965 models.
• The original Porsche exhaust system was engineered to balance performance, exhaust noise, emissions control and normal road usability.
• For dedicated competition vehicles, a shorter and less restrictive exhaust outlet may provide benefits where motorsport regulations permit its use.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FSPOR964TZMB

The product you are viewing cross references to these numbers

Fabspeed Primary Muffler Bypass Pipe.
The Fabspeed Porsche 964 Carrera Primary Muffler Bypass Pipe is a performance exhaust upgrade designed to replace the heavy and restrictive factory centre primary muffler with a lightweight, free-flowing Carrera Cup-style straight pipe.

Fits:

• Porsche 964 (911) C2 1989-94
• Porsche 964 (911) C4 1989-94

Inspired by the exhaust arrangement used on Porsche 964 Carrera Cup competition cars, the bypass pipe reduces exhaust restriction, removes substantial weight from the rear of the vehicle and produces a stronger, more aggressive air-cooled flat-six exhaust note.

Unlike a catalytic-converter bypass pipe, this component is installed after the catalytic converter and does not remove the vehicle's catalyst.

What This Product Does:
The standard Porsche 964 exhaust system uses a primary centre muffler to reduce exhaust noise before gases continue towards the secondary rear muffler.

While effective for noise reduction and refinement, the factory primary muffler adds weight and creates additional restriction in the exhaust path.

The Fabspeed Primary Muffler Bypass Pipe replaces this silencer with a freer-flowing straight pipe.

This is designed to:

• Reduce exhaust restriction
• Improve exhaust-gas flow
• Improve throttle response
• Support increased horsepower
• Reduce rear vehicle weight
• Increase exhaust volume
• Enhance the air-cooled flat-six sound
• Create a Carrera Cup-inspired exhaust configuration

Carrera Cup Style Design:

• The bypass pipe is designed as a replica of the type of primary muffler bypass arrangement used in the Porsche Motorsport 964 Carrera Cup racing programme.
• Rather than forcing exhaust gases through the internal chambers of a conventional silencer, the straight-pipe configuration provides a more direct exhaust route.
• This creates a more performance-oriented exhaust system while retaining the vehicle's catalytic converter and secondary rear muffler when used in the standard configuration.

Performance Benefits:
Fabspeed reports approximately:

Crank Horsepower: +12 HP
Wheel Horsepower: +10 WHP
Weight Reduction: Approx. 25 lb

Fabspeed also reports improved throttle response.

These figures are manufacturer-reported results from specific testing and should not be considered guaranteed output for every Porsche 964.

Actual performance can vary depending on:

• Engine condition
• Vehicle specification
• Existing exhaust components
• Intake modifications
• Engine calibration
• Fuel quality
• Ambient conditions
• Testing equipment and procedure

Why Upgrading Matters:
The Fabspeed Primary Muffler Bypass Pipe is primarily a performance, sound and weight-saving upgrade.

The original centre muffler does not need to have failed before the bypass pipe can be installed.

Reasons for upgrading include:

• Approx. 25 lb rear weight reduction
• Reduced exhaust restriction
• Improved exhaust flow
• Improved throttle response
• Increased horsepower potential
• More aggressive flat-six sound
• Carrera Cup-inspired configuration
• T304L stainless-steel construction
• Straightforward bolt-on installation

It provides a useful option for owners who want a noticeably sportier exhaust without deleting the catalytic converter.

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FSPOR964PMB

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Fabspeed RENNKRAFT Sport Cat And Comp.

The Fabspeed RENNKRAFT Sport Cat and Competition Link Pipe system is a performance exhaust upgrade designed for the Porsche 964 Turbo. It replaces the restrictive original catalytic converter section with Fabspeed's interchangeable RENNKRAFT system, allowing the exhaust configuration to be changed between an HJS 200-cell high-flow sport catalytic converter and a straight-through competition link pipe.

Fits:

• Porsche 964 (911) TURBO 3.3L 1990-94
• Porsche 964 (911) TURBO 3.6L 1990-94  

The sport catalyst configuration is designed to improve exhaust flow while retaining catalytic exhaust-gas treatment, while the competition link pipe provides the least restrictive exhaust path for appropriate track and competition use.

The system retains the original Porsche rear mufflers, allowing the vehicle to preserve a largely factory rear appearance while benefiting from reduced exhaust restriction, a stronger exhaust character and more noticeable turbocharger sound.

Constructed from 3-inch, 14–16 gauge T304L stainless-steel tubing, the system uses CNC mandrel bends to maintain a smooth internal exhaust path and provide durability under the high temperatures generated by the turbocharged flat-six engine.

What This Product Does:

• Replaces the restrictive original catalytic-converter section.
• Provides interchangeable sport-cat and competition-pipe configurations.
• Uses a high-flow HJS 200-cell catalytic converter in the catted configuration.
• Reduces exhaust restriction after the turbocharger.
• Helps improve exhaust-gas flow.
• Can help reduce turbo lag.
• Supports improved turbocharger response.
• Produces a more pronounced exhaust note.
• Increases audible turbo whistle.
• Retains the original Porsche rear mufflers.
• Allows the vehicle to maintain a relatively factory-looking rear exhaust installation.
• Provides a straight-through competition configuration for suitable track applications.
• Uses stainless-steel construction for long-term corrosion resistance.
• Provides a direct replacement for the factory catalytic-converter section.

Fabspeed states that the HJS 200-cell catalyst flows approximately 93% as much as a straight pipe, providing a balance between catalytic treatment and performance-oriented exhaust flow.

Symptoms Of Wear Or Failure:
A Porsche 964 Turbo's original catalytic converter can deteriorate after decades of heat cycles, vibration and exposure to high exhaust temperatures.

Possible signs of deterioration or restriction include:

• Reduced engine power.
• Sluggish acceleration.
• Slow turbo response.
• Increased turbo lag.
• Engine feeling restricted at higher RPM.
• Poor performance under heavy load.
• Excessive exhaust backpressure.
• Increased exhaust-gas temperatures.
• Unusual heat around the catalytic converter.
• Rattling from inside the converter.
• Metallic noises caused by a loose catalyst substrate.
• Strong or unusual exhaust smells.
• Failed emissions testing.
• Increased exhaust emissions.
• Visible corrosion or damage to the converter housing.
• Exhaust leaks around flanges or joints.

A partially blocked catalyst may allow relatively normal operation at low engine speeds but increasingly restrict exhaust flow as engine speed and load increase.

Why Replacement Matters:
The catalytic converter sits directly downstream within the turbocharged exhaust system, meaning its ability to flow exhaust gases can have a significant influence on engine and turbocharger performance.

As an old catalyst deteriorates, its internal substrate can:

• Break apart.
• Become contaminated.
• Melt or deform.
• Collapse internally.
• Become increasingly restrictive.

A restricted catalyst creates additional pressure after the turbocharger, making it more difficult for exhaust gases to leave the turbine efficiently.

Replacing an ageing or restrictive factory catalyst with a correctly designed high-flow system can help restore:

• Efficient exhaust flow.
• Turbocharger response.
• Throttle response.
• High-RPM performance.
• Correct exhaust-system operation.
• More consistent engine performance.
• A stronger performance exhaust character.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FSPOR964TSCCB

The product you are viewing cross references to these numbers

Fabspeed RSR Muffler Bypass Pipes.

The Fabspeed RSR Muffler Bypass Pipes are a motorsport-inspired exhaust upgrade for Porsche 911 964 Carrera models already equipped with the Fabspeed Maxflo RSR Header/Muffler Kit in its Non-Sport-Cat configuration.

Fits:

• Porsche 964 (911) C2 1989-94
• Porsche 964 (911) C4 1989-94

Designed to replace the Fabspeed mufflers with direct stainless-steel outlet pipes, they create a considerably less silenced exhaust path and give the air-cooled flat-six a much louder, more aggressive race-car character.

Rather than routing exhaust gases through conventional mufflers, the bypass pipes connect directly to the existing Fabspeed RSR headers. This reduces rear exhaust restriction and removes much of the sound attenuation provided by the mufflers.

The result is a raw, highly audible air-cooled exhaust note inspired by Porsche competition cars and intended primarily for drivers seeking maximum sound and a more direct motorsport experience.

Manufactured in-house by Fabspeed from T304L stainless steel, the pipes are designed for durability, heat resistance and straightforward bolt-on installation.

What This Product Does:
The RSR Muffler Bypass Pipes replace the muffler sections of the compatible Fabspeed exhaust with direct outlet pipes.

They are designed to:

• Eliminate the Fabspeed rear mufflers.
• Reduce rear exhaust restriction.
• Create a more direct exhaust path.
• Increase exhaust volume substantially.
• Produce a raw air-cooled flat-six sound.
• Give the vehicle an RSR / Cup-car-inspired exhaust character.
• Reduce the amount of sound attenuation in the exhaust system.
• Provide a lightweight and mechanically simple exhaust arrangement.
• Allow straightforward conversion back to the Fabspeed mufflers.
• Provide a bolt-on modification requiring no cutting or welding.

Symptoms Of Wear Or Failure:~
Possible symptoms include:

• Exhaust leaks.
• Ticking or blowing noises.
• Visible cracks.
• Cracked welds.
• Soot around joints.
• Loose V-band clamps.
• Excessive pipe movement.
• Exhaust vibration.
• Metallic rattling.
• Misaligned exhaust outlets.
• Pipework contacting bodywork.
• Dented or crushed tubing.
• Corrosion around mounting hardware.
• Exhaust smell around the rear of the vehicle.
• Increasing exhaust noise from an unintended leak rather than the outlet.

Because the pipes are intentionally loud, small leaks may be harder to identify by sound alone and should also be checked visually.

Why Replacement Matters:
Replacing damaged bypass pipes helps restore:

• Correct exhaust sealing.
• Proper system alignment.
• Unrestricted exhaust flow.
• Reliable V-band connections.
• Correct clearance from surrounding components.
• Structural integrity.
• Consistent exhaust sound.

On a vehicle used for performance driving or track events, maintaining exhaust integrity is particularly important because sustained high engine speeds create considerable exhaust heat.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FSPOR964RSRMB

The product you are viewing cross references to these numbers

Fabspeed Secondary Muffler Bypass Pipe.
The Fabspeed Porsche 964 Turbo / 965 / C2 Turbo Secondary Muffler Bypass Pipe is a performance exhaust upgrade designed to replace the factory secondary rear muffler with a freer-flowing stainless-steel pipe.

Fits:

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FSPOR964TSMB

The product you are viewing cross references to these numbers

Fabspeed Sport Highflow Catalytic Converter.
The Fabspeed Porsche 964 Carrera Sport High-Flow Catalytic Converter is a performance replacement for an ageing, damaged, missing or restrictive factory catalytic converter.

Fits:

• Porsche 964 (911) C2 1989-94
• Porsche 964 (911) C4 1989-94 

Designed to maintain catalytic emissions treatment while providing a freer-flowing exhaust path, the system combines a modern high-flow catalyst with CNC mandrel-bent T304L stainless-steel construction.

Compared with simply removing the catalytic converter, this system provides a performance-oriented solution that retains a functioning catalyst while improving exhaust flow and enhancing the characteristic air-cooled Porsche flat-six exhaust note.

What This Product Does:
A catalytic converter forms part of the vehicle's exhaust and emissions-control system.

Exhaust gases produced during combustion contain pollutants that need to be converted into less harmful compounds before leaving the exhaust.

The catalytic converter performs this emissions-treatment process while allowing exhaust gases to continue towards the rear silencer.

The Fabspeed Sport High-Flow Catalytic Converter performs this fundamental function while using a less restrictive performance-oriented design.

It is designed to provide:

• Catalytic emissions treatment
• Improved exhaust-gas flow
• Reduced exhaust restriction
• Improved engine breathing
• Increased horsepower potential
• Increased torque potential
• Improved throttle response
• Reduced exhaust-system weight
• Enhanced air-cooled flat-six sound

High-Flow Catalyst Design:

• The internal catalyst structure provides a large surface area for the chemical reactions required to process exhaust pollutants.
• A performance catalyst is engineered to achieve this while reducing the restriction placed on exhaust gases.
• This is particularly useful on a performance vehicle, where excessive exhaust backpressure can restrict engine breathing as airflow requirements increase.
• The Fabspeed system therefore provides an alternative to both a restrictive ageing factory catalyst and a catalyst-delete pipe.

Performance Benefits:
Fabspeed reports dyno-tested gains of:

Crank Horsepower: +28 HP
Wheel Horsepower: +24 WHP
Torque: +16 ft-lb
Weight Reduction: Approx. 9 lb

Fabspeed states that the power improvement occurs throughout the RPM range rather than being concentrated solely at maximum engine speed.

These are manufacturer-reported figures from a specific test vehicle and should not be interpreted as guaranteed results for every Porsche 964.

Actual performance can vary according to:

• Engine condition
• Existing exhaust system
• Intake modifications
• ECU calibration
• Fuel quality
• Ambient conditions
• Vehicle specification
• Testing equipment and procedure

Why Upgrading Matters:
The Fabspeed Sport High-Flow Catalytic Converter can also be installed as a performance upgrade even when the original catalyst remains functional.

Potential benefits include:

• Reduced exhaust restriction
• Improved exhaust flow
• Increased horsepower potential
• Increased torque potential
• Improved throttle response
• Reduced exhaust-system weight
• More sporting exhaust sound
• Modern catalyst technology
• Retention of catalytic emissions treatment

This makes it an alternative for owners seeking improved exhaust performance without moving to a catalyst-delete configuration.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FSPOR964SC

The product you are viewing cross references to these numbers

Fabspeed Turbo Link Comp. Pipe. 

The Fabspeed Porsche 964 Turbo / 965 / C2 Turbo Cat Bypass Pipe is a high-performance stainless steel exhaust component developed for Porsche 911 Turbo models manufactured between 1990 and 1994.

Fits:

• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93  

Designed by Fabspeed Motorsport, this competition exhaust pipe replaces the original Porsche catalytic converter with a freer-flowing exhaust connection between the K27 turbocharger and the factory secondary muffler.

Manufactured from premium 14–16 gauge T304L stainless steel, the bypass pipe features CNC mandrel-bent tubing and a 3.0-inch (76 mm) diameter to support efficient exhaust gas flow.

Its design incorporates a four-bolt flange connection and follows the concept of Porsche's original racing exhaust components.

By replacing the restrictive factory catalytic converter, the Fabspeed bypass pipe is designed to reduce exhaust backpressure downstream of the turbocharger, improve exhaust gas flow and enhance the distinctive sound of the turbocharged air-cooled flat-six engine.

The freer-flowing arrangement allows more of the turbocharger's characteristic whistle and spool-up sound to be heard, creating a more pronounced sports car exhaust character.

Fabspeed describes the system as producing an engaging exhaust note without becoming excessively loud when used with the compatible original rear muffler arrangement.

The bypass pipe is designed as a direct bolt-on replacement, allowing the original catalytic converter to be retained separately and refitted when required.

Its stainless steel construction provides resistance to corrosion and thermal deterioration, making it suitable for demanding competition environments.

The product is intended for owners of Porsche 964 Turbo and 965 vehicles seeking a dedicated competition exhaust configuration rather than a standard road-going catalytic converter replacement.

Important: This product removes the factory catalytic converter and is intended exclusively for closed-course motorsport and off-road applications where permitted. It must not be used on public roads.

What This Product Does:
The Fabspeed Cat Bypass Pipe replaces the factory catalytic converter with a straight-through, high-flow exhaust section.

Its primary function is to reduce exhaust restriction after the turbocharger, supporting freer exhaust gas movement towards the remaining exhaust system.

Its main functions and benefits include:

• Improved Exhaust Gas Flow: Replaces the factory catalytic converter with a less restrictive exhaust passage.
• Reduced Exhaust Backpressure: Helps reduce resistance to exhaust gases downstream of the turbocharger.
• Enhanced Turbocharger Sound: Makes turbo spool-up and whistle more noticeable.
• Improved Performance Potential: Reduced exhaust restriction may support improved power delivery under suitable operating conditions.
• Throttle Response Potential: A less restrictive exhaust arrangement may influence turbocharger response, although results depend on the engine and overall configuration.
• Sportier Exhaust Character: Produces a more pronounced turbocharged flat-six exhaust sound.
• Large-Diameter Tubing: Features 3.0-inch (76 mm) exhaust tubing.
• Smooth Exhaust Routing: CNC mandrel-bent construction helps maintain consistent tube geometry through bends.
• Durable Construction: T304L stainless steel provides corrosion resistance and suitability for high exhaust temperatures.
• Competition-Oriented Design: Based on the concept of Porsche factory racing exhaust components.
• Direct Bolt-On Fitment: Uses the original-style mounting arrangement without requiring permanent modification to the vehicle.
• Reversible Installation: Allows the original catalytic converter to be reinstalled when returning the vehicle to its road-approved configuration.

Symptoms Of Wear Or Failure:
The Fabspeed Cat Bypass Pipe is primarily a competition performance upgrade, not a standard maintenance replacement.

However, deterioration of the original catalytic converter or surrounding exhaust components may prompt owners to inspect or repair the existing system.

Common symptoms of catalytic converter or exhaust system problems include:

1. Reduced Engine Performance

A damaged or restricted catalytic converter may create excessive exhaust backpressure, potentially reducing engine performance.

Possible signs include sluggish acceleration, reduced power under load and difficulty maintaining normal performance at higher engine speeds.

2. Restricted Exhaust Flow

A physically damaged or obstructed catalytic converter may prevent exhaust gases from passing through the system normally.

In severe cases, this can affect the performance of a turbocharged engine.

3. Metallic Rattling from the Exhaust

An ageing catalytic converter may develop damaged or loose internal components.

These can produce rattling or metallic noises, particularly during acceleration or changes in engine speed.

4. Visible Corrosion

Older exhaust components may develop rust or corrosion due to moisture, road salt and repeated heating and cooling.

Severe deterioration can weaken pipework, joints and mounting points.

5. Exhaust Leaks

Cracked components, deteriorated gaskets or damaged flange connections may allow exhaust gases to escape.

Symptoms can include unusual blowing noises, increased exhaust volume and escaping fumes.

6. Unusual Exhaust Smells

Changes in exhaust odour may indicate catalytic converter deterioration, an exhaust leak or an underlying engine combustion problem.

The cause should be diagnosed before replacing components.

7. Excessive Exhaust Heat

An internally restricted catalytic converter can contribute to abnormal temperature conditions within the exhaust system.

Severe overheating may damage surrounding components and should be investigated promptly.

8. Damaged Mounting Connections

Corroded fasteners, damaged flanges or deteriorated exhaust mountings may compromise the security of the original catalytic converter.

9. Poor Turbocharger Response

Excessive exhaust restriction can affect turbocharger operating conditions.

However, reduced boost response may also be caused by turbocharger wear, boost leaks, wastegate faults or fuel and ignition problems.

10. Visible Impact Damage

Ground clearance issues, road debris or previous accidents may damage the original catalytic converter or adjacent exhaust pipework.

Why Replacement / Upgrading Matters:

• Maintaining a correctly functioning exhaust system is important for engine performance, turbocharger operation, structural integrity and vehicle safety.
• On the Porsche 964 Turbo and 965, exhaust gases pass through the turbocharger before flowing into the downstream exhaust system.
• The factory catalytic converter reduces harmful exhaust emissions while also forming part of the original exhaust routing.
• In competition applications, a catalytic converter bypass may be used to reduce downstream exhaust restriction where permitted by motorsport regulations.

NOTE: In the United Kingdom, sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001. They are not MOT compliant and cannot be used on public roads. These components are intended solely for race and track use.

For vehicles manufactured before 1st March 2001, a non-type approved sports catalytic converter may be fitted, provided it offers comparable performance to the original and the vehicle continues to meet the applicable emissions standards for its age. The vehicle must still pass an MOT test.

If you are located outside the UK, please check your local laws and regulations to ensure compliance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FSPOR964TCB

The product you are viewing cross references to these numbers

Intermediate Pipe replacement in stainless steel. Grey painted.

Fits:
Porsche 930 3.0L Turbo 1975-77
Porsche 930 3.3L Turbo 1978-89
Porsche 964 Turbo 3.3L-3.6L 06/1991-07/1993

Please note:
This part will fit most of cars straight away but some may require alteration.
Porsche made a few different versions of the pipe over the years which all had a slightly different shape. (although Porsche used one number)
If this pipe is out you would need to loosen all the bolts on the exhaust system (Including the turbo) and mount the pipe into place afterwards.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

93011100304

The product you are viewing cross references to these numbers