Catalyst / Bypass

Fabspeed Competition Link Pipe X-Pipe.
The Fabspeed Porsche 996 Carrera Competition Link Pipe / Cat Bypass X-Pipe is a performance exhaust component designed for closed-course competition and off-road applications. It replaces the factory catalytic-converter section with a freer-flowing X-pipe, reducing exhaust restriction and allowing the Porsche flat-six engine to breathe more efficiently at higher engine speeds.

Fits:

• Porsche 996 C2 3.6L 1999-2004
• Porsche 996 C4 3.6L 1999-2004 

Manufactured from mandrel-bent T304L stainless steel, the system is designed to improve mid- and high-RPM performance, sharpen throttle response, reduce rear-end weight and create a significantly more aggressive exhaust note.

Because this system eliminates the factory catalytic converters, it is intended strictly for closed-track and off-road use where legally permitted and should not be used on public roads where catalytic converters are required.

What This Product Does:
The standard Porsche 996 Carrera exhaust system uses catalytic converters to reduce harmful exhaust emissions.

For dedicated competition applications, the Fabspeed Cat Bypass X-Pipe replaces this catalytic-converter section with unrestricted exhaust tubing and an X-pipe crossover.

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

The system is designed to:

• Reduce exhaust backpressure
• Improve exhaust-gas flow
• Improve mid- and high-RPM performance
• Increase horsepower potential
• Increase torque
• Improve throttle response
• Reduce exhaust-system weight
• Produce a louder, more aggressive exhaust note
• Improve high-RPM engine breathing

Performance Benefits:
Fabspeed reports dyno-tested improvements of:

Horsepower: +33 WHP
Torque: +41 ft-lb
Weight Reduction: Approx. 25 lb

Fabspeed states that the system was developed to deliver its strongest gains towards the upper part of the rev range, with substantial improvements above approximately 3,500 rpm.

These are manufacturer-reported results from a particular test vehicle and are not guaranteed figures for every Porsche 996 Carrera.

Actual performance can vary according to engine condition, vehicle specification, existing modifications, ECU calibration, fuel, atmospheric conditions and testing method.

Why Upgrading Matters:
This component is primarily a competition performance upgrade, not a routine replacement for a failed factory catalytic converter.

For suitable closed-course vehicles, potential reasons for installation include:

• Reduced exhaust restriction
• Increased high-RPM exhaust flow
• Improved mid- and high-RPM performance
• Reduced rear-end weight
• Sharper throttle response
• More aggressive exhaust sound
• Simplified competition exhaust configuration

It can also form part of a broader competition exhaust package incorporating performance headers, lightweight mufflers and other track-oriented modifications.

Fabspeed Link Comp X-Pipe.
The Fabspeed Porsche 996 GT3 Cat Bypass X-Pipe is a high-performance competition exhaust component designed to replace the factory catalytic converters with a freer-flowing X-pipe arrangement.

Fits:

• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>  

Developed for track and competition-focused Porsche 996 GT3 applications, the system removes the restrictive catalytic-converter section and provides a more direct route for exhaust gases leaving the engine.

By reducing exhaust restriction and allowing gases from both cylinder banks to merge through the X-pipe, the system is designed to improve exhaust flow, sharpen throttle response, reduce weight and produce a considerably more aggressive GT3 exhaust note.

What This Product Does:
The original catalytic converters form part of the vehicle's emissions-control system.

While catalysts treat exhaust gases, their internal substrates also create resistance to exhaust flow.

The Fabspeed Cat Bypass X-Pipe removes this catalytic restriction and replaces it with freer-flowing exhaust pipework.

The system is designed to:

• Remove the restrictive factory catalytic converters
• Increase exhaust-gas flow
• Reduce exhaust backpressure
• Improve engine breathing
• Improve throttle response
• Increase horsepower and torque potential
• Reduce exhaust-system weight
• Increase exhaust volume
• Produce a more aggressive motorsport-inspired sound

Because the catalytic converters are removed, this is fundamentally different from a Sport Cat system.

X-Pipe Design:
An X-pipe connects the exhaust streams from the two cylinder banks.

Rather than keeping both exhaust paths completely separate, the crossover allows pressure pulses from each bank to interact.

A properly designed X-pipe can help:

• Balance exhaust pulses
• Improve gas-flow transitions
• Reduce turbulence
• Improve exhaust scavenging
• Support high-RPM performance
• Create a smoother, more exotic exhaust tone

This is particularly suited to the naturally aspirated, high-revving flat-six engine used in the 996 GT3.

Maximum Exhaust Flow:
Removing the catalytic substrates eliminates one of the major restrictions in the exhaust system.

This creates a substantially more open exhaust route.

Potential benefits include:

• Reduced exhaust backpressure
• Faster exhaust evacuation
• Improved engine breathing
• Sharper throttle response
• Stronger high-RPM performance
• Increased performance potential

Actual performance depends on the complete vehicle configuration.

Why Upgrading Matters:
The factory catalytic converters do not need to have failed for this component to be installed.

The Cat Bypass X-Pipe is primarily a competition performance upgrade.

Reasons for upgrading include:

• Maximum exhaust-gas flow
• Elimination of catalytic-converter restriction
• Reduced exhaust backpressure
• Improved throttle response potential
• Increased horsepower and torque potential
• Reduced exhaust-system weight
• More aggressive GT3 exhaust sound
• Improved high-RPM exhaust character
• X-pipe crossover design
• Track-focused configuration

It is particularly suited to vehicles where performance and exhaust flow take priority over road-use emissions requirements.

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.

FSPOR996GT3CBX

The product you are viewing cross references to these numbers

Fabspeed Muffler Bypass Pipes.

The Fabspeed Muffler Bypass Pipes are a performance-focused exhaust upgrade designed for compatible Porsche 996 Turbo, X50 and GT2 applications.

Fits:

• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05  

These straight-through pipes replace the Fabspeed Maxflo rear mufflers, creating a much more direct exhaust path from the Fabspeed Sport Catalytic Converters to the exhaust tips. Removing the mufflers substantially increases exhaust volume and gives the 996 Turbo a raw, aggressive motorsport-inspired sound.

The system also removes a considerable amount of rear exhaust weight. Fabspeed states that this configuration saves approximately 50 lb compared with the standard 996 Turbo exhaust system.

These bypass pipes are specifically designed as part of the Fabspeed modular exhaust system. Existing Fabspeed Sport Catalytic Converters are required, and the pipes will not directly fit the original Porsche exhaust or other aftermarket 996 Turbo systems.

What This Product Does:
A conventional rear muffler reduces exhaust noise by forcing exhaust gases through internal chambers, perforated tubes or sound-absorbing structures.

The Fabspeed Muffler Bypass Pipes eliminate the rear mufflers and provide a much more direct path for exhaust gases to travel towards the tailpipes.

Their primary functions and benefits include:

• Eliminating the Fabspeed Maxflo rear mufflers
• Creating a freer and more direct exhaust route
• Producing a considerably louder and more aggressive exhaust note
• Reducing rear exhaust system weight
• Allowing reuse of compatible factory, aftermarket or Fabspeed exhaust tips
• Providing a motorsport-inspired exhaust character
• Allowing compatible Fabspeed systems to be converted between muffled and bypass configurations

Fabspeed specifically designed the system to be interchangeable, allowing owners with the required Fabspeed components to change between a muffler and muffler-bypass arrangement.

Symptoms Of Wear Or Failure:
Exhaust bypass pipes contain fewer internal components than conventional mufflers, but they are still exposed to extreme heat, vibration, moisture and road contamination.

Signs that the bypass pipes or their connections may require attention include:

• Cracks around welds or pipe joints
• Exhaust blowing or hissing sounds
• Black soot around leaking connections
• Loose clamps or mounting hardware
• Excessive movement or vibration
• Metallic rattling from loose mounting points
• Visible corrosion or surface deterioration
• Dents or impact damage to the pipework
• Exhaust tips becoming incorrectly aligned
• Exhaust fumes escaping from joints before the tailpipes
• Unusual changes in exhaust sound
• Pipes contacting surrounding bodywork or heat shields

If the vehicle is still fitted with its original mufflers, deterioration may instead appear as rattling internal components, corrosion, cracking, exhaust leaks or damage to the muffler casing.

Why Replacement / Upgrading Matters:

• A damaged exhaust pipe or leaking connection can allow hot exhaust gases to escape before reaching the intended outlets. This can create unwanted noise, soot deposits and additional heat around nearby components.
• Cracked or poorly supported exhaust components can also move excessively and place additional load on mounting brackets, joints and surrounding parts.
• Where the existing Fabspeed Maxflo system is in good condition, fitting the Muffler Bypass Pipes is primarily a performance-sound and weight-reduction upgrade rather than a necessary repair. The bypass configuration removes the rear mufflers and gives the 996 Turbo a significantly more aggressive exhaust character.
• For owners using their vehicle for performance driving or seeking a more dramatic exhaust note, the reduced restriction and considerable weight saving can make the bypass configuration particularly attractive.
• If replacing worn or damaged exhaust components, restoring secure, correctly aligned pipework also ensures that exhaust gases are directed safely to the rear of the vehicle.

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

FSPOR996TMB

The product you are viewing cross references to these numbers

Fabspeed Sport Cat X-Pipe.
The Fabspeed Porsche 996 GT3 Sport Cat X-Pipe is a high-performance catalytic converter and X-pipe upgrade designed to improve exhaust flow, throttle response, power and exhaust sound while retaining catalytic exhaust treatment.

Fits:

• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>  

Replacing the original catalytic-converter section, the system combines 200-cell HJS high-flow Sport Catalytic Converters with a specially designed stainless-steel cast X-pipe featuring a knife-edged internal design. The result is a less restrictive exhaust path that allows gases from the naturally aspirated GT3 flat-six to flow more efficiently through the exhaust system.

Manufactured using mandrel-bent T304L stainless steel, the system is designed as a direct bolt-on performance upgrade requiring no cutting or welding.

Fabspeed reports gains of up to 15 wheel horsepower, together with approximately 14 lb-ft of torque and a 12 lb weight reduction compared with the factory components. Actual results depend on the individual vehicle and testing conditions.

What This Product Does:
The catalytic converters sit within the exhaust system and process exhaust gases before they leave the vehicle.

At the same time, their internal construction creates some resistance to exhaust flow.

A performance Sport Cat system aims to maintain catalytic treatment while reducing unnecessary restriction compared with the original catalytic-converter arrangement.

The Fabspeed Sport Cat X-Pipe is designed to:

• Improve exhaust-gas flow
• Reduce exhaust restriction
• Improve throttle response
• Increase horsepower and torque potential
• Reduce exhaust-system weight
• Produce a more defined GT3 exhaust note
• Provide a mild increase in exhaust volume
• Retain catalytic exhaust treatment
• Improve exhaust flow between the two cylinder banks

Manufacturer Report Performance:
Fabspeed reports curve gains of up to approximately:

Power: +15 WHP
Torque: +14 lb-ft
Weight Reduction: Approx. 12 lb

These are manufacturer-reported figures and should not be interpreted as guaranteed gains for every vehicle.

Actual performance can vary according to:

• Engine condition
• Existing exhaust configuration
• Headers
• Rear muffler system
• Intake modifications
• Engine calibration
• Fuel quality
• Ambient conditions
• Vehicle specification
• Dyno equipment and testing procedure

Why Upgrading Matters:
The factory catalytic converters do not need to have failed for this system to be installed.

The Fabspeed Sport Cat X-Pipe is primarily a performance upgrade designed for drivers seeking improved exhaust flow without moving to a completely catless exhaust section.

Reasons for upgrading include:

• 200-cell HJS Sport Catalytic Converters
• Reduced exhaust restriction
• Cast stainless-steel X-pipe
• Knife-edged X-pipe design
• Improved exhaust-gas flow
• Improved throttle response
• Manufacturer-reported gains up to +15 WHP
• Manufacturer-listed +14 lb-ft torque
• Approx. 12 lb weight reduction
• More defined GT3 exhaust sound
• Mild increase in exhaust volume
• T304L stainless-steel construction
• Mandrel-bent tubing
• Direct bolt-on installation
• No cutting or welding required

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

FSPOR996GT3SCX

The product you are viewing cross references to these numbers

Fabspeed Sport Catalytic Converter X-Pipe.
The Fabspeed Porsche 996 Carrera Sport Catalytic Converter X-Pipe is a high-performance exhaust upgrade designed to replace the restrictive factory catalytic-converter section while retaining catalytic emissions treatment.

Fits:

• Porsche 996 C2 3.6L 1999-2004
• Porsche 996 C4 3.6L 1999-2004

Combining a specially developed X-pipe crossover with integrated 200-cell HJS Sport Catalytic Converters, the system is designed to improve exhaust-gas flow, increase horsepower and torque, reduce rear-end weight and enhance the distinctive Porsche flat-six exhaust note.

Constructed from mandrel-bent T304L stainless-steel tubing, the system provides a performance-focused alternative to the factory catalytic converters without using catalyst-bypass pipes.

What This Product Does:
The catalytic-converter section performs two important functions within the exhaust system.

First, it routes exhaust gases from the engine towards the rear mufflers. Second, the catalytic converters chemically process harmful exhaust pollutants before the gases leave the vehicle.

The Fabspeed Sport Catalytic Converter X-Pipe retains catalytic-converter functionality while providing a higher-flow exhaust path.

Its design is intended to:

• Reduce exhaust restriction
• Improve exhaust-gas flow
• Improve mid-range torque
• Improve high-RPM horsepower
• Enhance throttle response
• Reduce exhaust-system weight
• Produce a more sporting flat-six exhaust note
• Retain catalytic emissions treatment

Performance Benefits:
Fabspeed reports dyno-tested improvements of:

Horsepower: +25 WHP
Torque: +32 ft-lb
Weight Reduction: Approximately 11 lb

These figures are manufacturer-reported results and should not be considered guaranteed output for every vehicle.

Actual performance can vary depending on:

• Engine condition
• Vehicle specification
• Fuel quality
• Existing exhaust modifications
• Intake modifications
• ECU calibration
• Ambient conditions
• Dyno type and testing procedure

Why Upgrading Matters:
The Fabspeed Sport Catalytic Converter X-Pipe is also a performance upgrade, meaning the original catalytic converters do not need to have failed before the system can be installed.

Owners may choose the upgrade for:

• Increased exhaust flow
• Reduced exhaust restriction
• Improved mid-range torque
• Improved high-RPM horsepower
• Enhanced flat-six exhaust sound
• Reduced exhaust-system weight
• High-flow HJS catalytic converters
• Performance-oriented X-pipe design

It can also complement other upgrades such as performance headers, rear mufflers, intake modifications and suitable ECU calibration.

Lambda Sensor Blanking Plug and Receiver Socket Set.
In case you need to relocate your existing lambda probe because it's not in the right location. Welding and cutting specialist required.


Fits:
Many Porsche vehicles. Universal kit.

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

100390100392

The product you are viewing cross references to these numbers

Standard Replacement Exhaust Catalytic Converter for Porsche 996 3.4L 400 Cell
Not suitable for cars with stricter emissions M661



We recommend you change cats in a pair. For cars with only 2 lambda sensors like the Porsche Carrera 996 3.4L models please also buy Code:  EXHFITTING.996.1.1

PORSCHE 996 Carrera 3.4L Replacement Cats made in grade 409 stainless steel.

Fits:
Porsche Carrera 3.4L

Our cat is made up of the following components:

• Ceramic monolith of a honeycomb design to allow free air flow and maximum surface area, coated with precious metals to enable the conversion of gasses that pass through it
• Interam matting to hold the monolith in place. The matting expands when exposed to heat to supply the pressure needed to keep the monolith secure
• A grade 409 stainless steel can (or housing) to provide protection and enable the cat to be built into the exhaust system. 409 grade can contain upto 90% iron and will be prone to rust. It still has higher rust-resistant properties than mild steel.

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

99611302

The product you are viewing cross references to these numbers