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Porsche > 996 (911) (1997-2005) > 996 TURBO 2000-05 > Exhausts >

Catalyst / Bypass

Catalyst / Bypass

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DISPLAYING 1 to 3 (of 3 products)
Exhaust heat shield. Porsche 996 Turbo - 99611120572, 99611120672
4
Exhaust heat shield. Porsche 996 Turbo
Special Order item
99611120
Product Information
Product Information
Exhaust heat shield for Silencer with catalyst



Fits:
Porsche 996 Turbo 2001-05

Click 'Zoom in' for large parts diagram.
Diagram ref no 19

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Related, superseded, cross reference or alternative numbers for comparison.

99611120
99611120572
99611120672

The product you are viewing cross references to these numbers
Fabspeed Muffler Bypass Pipes. Porsche 996 Turbo (2000-2005) - 99611102775, 99611102776, 99611198775, 99611198777 - FS.POR.996T.MB
1
Fabspeed Muffler Bypass Pipes. Porsche 996 Turbo (2000-2005)
FSPOR996TMB
Product Information
Product Information
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
99611102775
99611102776
99611198775
99611198777

The product you are viewing cross references to these numbers
Lambda Sensor Blanking Plug and Receiver Socket. Porsche 996 / 997 - 100390, 100392
3
Lambda Sensor Blanking Plug and Receiver Socket. Porsche 996 / 997
100390100392
Product Information
Product Information
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
100390
100392

The product you are viewing cross references to these numbers
DISPLAYING 1 to 3 (of 3 products)
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About Catalyst / Bypass

Exhaust Catalytic Converters & Bypass Pipes – Performance, Efficiency & Flow Control

The catalytic converter plays a crucial role in your Porsche’s exhaust system, reducing harmful emissions while maintaining optimal exhaust flow. Positioned between the exhaust manifold and silencer, it converts toxic gases such as carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful emissions before they exit the tailpipe.

At Design911, we offer a complete range of catalytic converters and bypass pipes for Porsche vehicles. Our manufacturer-quality converters ensure reliable emission control and long-term performance, while our bypass options are designed for track or performance use, optimising exhaust flow for maximum power and throttle response.

Whether you’re maintaining your Porsche to meet emissions standards or upgrading for improved exhaust performance, our selection includes both direct-fit converters and performance bypass kits built from high-grade stainless steel for strength, corrosion resistance, and durability.

What Do Catalytic Converters & Bypass Pipes Do?

A catalytic converter uses a fine mesh of precious metals to trigger chemical reactions that break down pollutants. The bypass alternative eliminates restriction in the exhaust flow, improving performance in non-emissions-controlled environments such as track driving.

Core Functions:

  • Converts toxic exhaust gases into environmentally friendly emissions.
  • Maintains exhaust back pressure for engine efficiency.
  • Reduces harmful NOx, CO, and HC emissions.
  • Supports smoother engine performance and throttle control.
  • Bypass versions enhance exhaust flow and improve power output for track cars.

Upgrading to a performance-grade system ensures your Porsche continues to meet emission requirements — or achieves greater flow and responsiveness for motorsport applications.

Why Do Catalytic Converters Fail?

Catalytic converters are exposed to extreme heat, unburnt fuel, and contaminants — all of which can degrade their performance over time.

Common Causes of Failure Include:

  • Carbon or oil buildup blocking the internal honeycomb.
  • Thermal damage from overheating or rich fuel mixtures.
  • Physical damage from road debris or misfiring engines.
  • Corrosion due to moisture and exhaust condensation.
  • Age-related wear reducing catalytic efficiency.

A failing converter can cause reduced engine power, poor fuel economy, rattling sounds, or a check-engine light. Replacing it restores emissions compliance, performance, and exhaust efficiency.

Why Replace or Upgrade with Precision-Engineered Components?

Replacing a failing converter or upgrading to a bypass pipe ensures your Porsche maintains peak performance and reliability.

Key Benefits:

  • Restores optimal emissions performance and efficiency.
  • Improves exhaust flow and throttle response.
  • Reduces engine stress and fuel consumption.
  • Durable stainless-steel construction for longevity.
  • Direct-fit compatibility for Porsche 911, Cayman, Boxster, Panamera, Macan and more.
  • Performance bypass options available for track and tuning applications.

Whether you want emissions compliance or maximum flow for competition use, our parts deliver reliability, precision, and performance.

Highlights:

  • Direct-fit catalytic converters and bypass pipes for Porsche models.
  • Precision-engineered for optimal flow and reduced emissions.
  • Built from heat-resistant stainless steel for durability.
  • Bypass pipes for performance tuning and track applications.
  • Restores power, efficiency, and exhaust sound balance.
  • Available for classic and modern Porsche vehicles.

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