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Catalyst / Bypass

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DISPLAYING 1 to 5 (of 5 products)
FSPOR9912GT2RSCB
Product Information
Product Information
Fabspeed Competition Link Pipes For PSE.

The Fabspeed Competition Link Pipes are a motorsport-focused catalyst-bypass exhaust upgrade designed for the Porsche 911 991.2 GT2 RS from 2018 onward.

Fits:

  • Porsche 991.2 GT2 RS 3.8L PDK (700 bhp) 2018-19  


Developed for maximum exhaust flow and an uncompromised competition sound, the system replaces the restrictive factory ceramic catalytic converters with straight-through stainless-steel link pipes while retaining the car's Porsche Sport Exhaust – PSE – valve functionality.

The original GT2 RS uses approximately 700-cell ceramic catalytic converters. Removing these high-density catalysts creates a much less restrictive route for exhaust gases leaving the turbochargers.

This can reduce exhaust backpressure, increase turbocharger sound and provide considerably greater flow potential for highly tuned or competition vehicles.

Unlike basic straight pipes, the Fabspeed system incorporates large 74mm / 2.92in Helical Limited UK exhaust valves, compared with approximately 60mm / 2.375in factory valves.

These larger valves allow increased exhaust flow while retaining the ability to control the exhaust path through the Porsche PSE system.

What This Product Does:
The Fabspeed Competition Link Pipes replace the factory catalytic converter assemblies located downstream of the GT2 RS turbochargers.

They are designed to:

  • Remove the restriction created by the factory catalytic converters.
  • Reduce exhaust backpressure.
  • Increase exhaust gas flow.
  • Improve turbocharger outlet flow.
  • Support quicker turbo response.
  • Increase performance potential on tuned vehicles.
  • Increase turbocharger whistle and spool sound.
  • Produce a substantially louder exhaust note.
  • Retain Porsche Sport Exhaust valve functionality.
  • Replace the smaller factory exhaust valves with larger Helical valves.
  • Reduce exhaust-system weight.
  • Provide a modular competition exhaust configuration.

Symptoms Of Wear Or Failure:
Although straight exhaust pipes contain fewer internal components than catalytic converters, they can still deteriorate or become damaged.

Possible symptoms include:

  • Exhaust leaks.
  • Ticking or blowing noises.
  • Soot around joints or welds.
  • Metallic rattling.
  • Cracked welds.
  • Damaged tubing.
  • Loose clamps.
  • Excessive exhaust movement.
  • Pipes becoming misaligned.
  • Contact with heat shields or bodywork.
  • Exhaust valve rattling.
  • Valve sticking.
  • One exhaust bank sounding different from the other.
  • PSE no longer changing the exhaust sound correctly.
  • Excessive vibration around the valve assemblies.

Why Replacement Matters:
A damaged competition link pipe can compromise the performance and reliability of the exhaust system.

Replacing worn or damaged components helps restore:

  • Correct exhaust sealing.
  • Proper valve function.
  • Maximum intended flow.
  • Consistent PSE operation.
  • Correct pipe alignment.
  • Safe clearance from nearby components.
  • Structural integrity.

On a high-performance turbocharged vehicle, exhaust integrity is particularly important because of the high temperatures and gas velocities involved.

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.

FSPOR9912GT2RSCB
9P1254400B
9P1254400E
9P1254450B
9P1254450E

The product you are viewing cross references to these numbers
FSPOR9912GT2RSRACECB
Product Information
Product Information
Fabspeed Competition Link Pipes.

The Fabspeed Competition Cat Bypass Race Pipes are an extreme motorsport exhaust upgrade designed specifically for the Porsche 911 991.2 GT2 RS from 2018 onward.

Fits:

  • Porsche 991.2 GT2 RS 3.8L PDK (700 bhp) 2018-19  

The Fabspeed Competition Cat Bypass Race Pipes are an extreme motorsport exhaust upgrade designed specifically for the
Porsche 911 991.2 GT2 RS from 2018 onward.

Developed for maximum exhaust flow, minimum restriction and significant weight reduction, the system replaces both the restrictive factory 700-cell ceramic catalytic converters and the original titanium centre muffler with lightweight straight-through race pipes.

Unlike Fabspeed's PSE-compatible Competition Link Pipes, this version uses no exhaust valves. Removing the catalytic converters, centre muffler and valve assemblies creates the most direct possible exhaust route from each turbocharger to the rear outlets.

The result is substantially reduced backpressure, faster turbo response, significantly increased exhaust volume and a much more aggressive motorsport-style character.

Fabspeed currently lists gains of approximately:

+24 WHP

+29 lb-ft of torque

19 lb weight reduction

Fabspeed also states that when the Competition Cat Bypass Race Pipes are combined with its ECU calibration, its test vehicle produced more than 750 HP at the wheels and approximately 863 HP at the crank.

Actual performance will vary according to vehicle condition, fuel, calibration, environmental conditions and supporting modifications.

What This Product Does:
The Fabspeed Competition Race Pipe system replaces a substantial portion of the original GT2 RS exhaust system.

It is designed to:

  • Remove the restrictive factory catalytic converters.
  • Remove the factory titanium centre muffler.
  • Eliminate exhaust valve restrictions.
  • Create an essentially straight-through exhaust path.
  • Reduce post-turbo exhaust backpressure.
  • Increase exhaust gas flow.
  • Improve turbocharger spool.
  • Improve throttle response.
  • Reduce exhaust-system weight.
  • Produce maximum GT2 RS exhaust volume.
  • Increase audible turbocharger whistle and spool.
  • Support highly tuned competition vehicles.
  • Provide quick conversion between race and original exhaust configurations.

Symptoms Of Wear Or Failure:
Race pipes have fewer internal components than catalytic converter assemblies, but they can still suffer mechanical damage.

Possible symptoms include:

  • Exhaust leaks.
  • Ticking or blowing noises.
  • Cracked welds.
  • Damaged tubing.
  • Loose clamps.
  • Soot around joints.
  • Excessive vibration.
  • Pipes becoming misaligned.
  • Exhaust outlets moving out of position.
  • Rattling against surrounding components.
  • Excessive exhaust movement.
  • Impact damage.
  • Heat-related stress cracking.

Why Replacement Matters:
Replacing a damaged competition pipe helps restore:

  • Maximum intended exhaust flow.
  • Correct exhaust sealing.
  • Safe hot-gas routing.
  • Proper component alignment.
  • Structural integrity.
  • Correct outlet positioning.
  • Reduced risk of heat damage.

For a GT2 RS used regularly on circuit, exhaust inspection should form part of routine maintenance.

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.

FSPOR9912GT2RSRACECB
9P1254400B
9P1254400E
9P1254450B
9P1254450E

The product you are viewing cross references to these numbers
FSPOR9912GT2RSRACESC
Product Information
Product Information
Fabspeed Non-Valved Sport Cats. 

The Fabspeed Non-Valved Sport Cats are a high-performance exhaust and catalytic-converter upgrade developed specifically for the Porsche 911 991.2 GT2 RS from 2018 onward.

Fits:

  • Porsche 991.2 GT2 RS 3.8L PDK (700 bhp) 2018-19  


Designed for owners who want significantly improved exhaust flow and a more aggressive sound while retaining catalytic converters, the system replaces the restrictive factory 700-cell ceramic catalysts and OEM titanium centre muffler with large German HJS 200-cell high-flow catalytic converters and direct rear exhaust outlets.

Unlike Fabspeed's valved GT2 RS sport-cat system, this version contains no exhaust valves. Exhaust gases therefore follow a direct, unrestricted path through the high-flow catalysts and towards the rear outlets at all times.

The HJS catalysts use a high-performance tri-metallic substrate and are designed to provide very high exhaust flow while maintaining catalytic treatment. Fabspeed states that the 200 CPSI HJS cores can flow approximately 90–93% of a straight pipe in suitable applications.

The system is fabricated from 14–16 gauge CNC mandrel-bent T304 stainless steel and includes both angle-cut outlets and slip-on 90-degree turn-down outlets.

Fabspeed currently reports hardware-only gains of:

+7 WHP

+10 lb-ft of torque

Approximately +8.5 HP and +12 lb-ft at the engine

Approximately 12 lb weight reduction

When combined with Fabspeed ECU tuning, the manufacturer also states that its test configuration has produced over 740 HP at the wheels and approximately 850–888 HP at the crank on pump fuel.

Actual performance will vary according to vehicle condition, fuel, calibration, environmental conditions and other modifications.

What This Product Does:
The Fabspeed Non-Valved Sport Cat system replaces the factory catalytic-converter and centre-muffler arrangement downstream of the GT2 RS turbochargers.

It is designed to:

  • Reduce exhaust restriction.
  • Replace the factory 700-cell catalysts.
  • Replace the OEM titanium centre muffler.
  • Retain catalytic exhaust treatment.
  • Reduce post-turbo backpressure.
  • Improve exhaust gas flow.
  • Improve turbocharger response.
  • Sharpen throttle response.
  • Increase engine performance potential.
  • Produce a significantly stronger exhaust note.
  • Increase audible turbocharger spool and whistle.
  • Reduce exhaust-system weight.
  • Eliminate exhaust-valve restriction.
  • Provide a direct exhaust route from the turbochargers to the rear outlets.

Symptoms Of Wear Or Failure:
Possible signs of catalytic-converter deterioration include:

  • Check Engine Light.
  • Catalyst-efficiency fault codes.
  • Loss of engine performance.
  • Sluggish throttle response.
  • Slower turbocharger response.
  • Engine feeling restricted under boost.
  • Reduced high-RPM power.
  • Increased exhaust backpressure.
  • Metallic rattling from inside the catalyst.
  • Unusual exhaust smells.
  • Excessive catalyst temperature.
  • Internal substrate breaking apart.
  • Melted or collapsed catalyst material.
  • Failed emissions testing where applicable.

Why Replacement Matters:
Replacing a failed or restricted catalytic converter helps restore:

  • Correct exhaust flow.
  • Turbocharger efficiency.
  • Engine performance.
  • Exhaust-system sealing.
  • Reliable catalytic operation.

Upgrading to the Fabspeed system additionally provides:

  • Significantly reduced catalyst restriction.
  • Improved throttle and turbo response.
  • More aggressive exhaust sound.
  • Lower exhaust-system weight.
  • Durable stainless-steel construction.
  • Catalytic treatment without a fully catalyst-free race-pipe configuration.

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.

FSPOR9912GT2RSRACESC
9P1254400B
9P1254400E
9P1254450B
9P1254450E

The product you are viewing cross references to these numbers
FSPOR9912GT2RSSC
Product Information
Product Information
Fabspeed Valved Sport Cats.

The Fabspeed Valved Sport Catalytic Converters are a high-performance replacement for the factory catalytic converter assemblies fitted to the Porsche 911 991.2 GT2 RS from 2018 onward.

Fits:

  • Porsche 991.2 GT2 RS 3.8L PDK (700 bhp) 2018-19


Designed specifically for the high-output twin-turbocharged GT2 RS, the system replaces the restrictive factory 700-cell ceramic catalytic converters with significantly freer-flowing German HJS 200 CPSI sport catalytic converters.

The reduced catalyst density allows exhaust gases to pass through the system with less restriction, helping reduce backpressure downstream of the turbochargers, improve turbo response and provide a stronger, more aggressive exhaust note.

Unlike a basic high-flow catalyst conversion, the Fabspeed system also retains the car's Porsche Sport Exhaust (PSE) functionality through high-temperature Helical UK exhaust valves.

Fabspeed uses larger exhaust valves than the factory arrangement to increase available exhaust flow when the valves are open while maintaining driver-controlled exhaust operation.

The system is constructed from 14–16 gauge CNC mandrel-bent T304 stainless steel and bolts directly to the original GT2 RS titanium centre muffler.

What This Product Does:
The sport catalytic converter system replaces the original catalytic converter assemblies immediately downstream of the turbochargers.

It is designed to:

  • Reduce exhaust restriction.
  • Reduce turbocharger outlet backpressure.
  • Improve exhaust gas flow.
  • Support quicker turbocharger response.
  • Improve throttle response.
  • Support increased horsepower and torque.
  • Produce a stronger GT2 RS exhaust note.
  • Retain catalytic exhaust treatment.
  • Maintain Porsche Sport Exhaust functionality.
  • Replace restrictive, damaged or failed factory catalytic converters.
  • Work with the original Porsche titanium centre muffler.
  • Provide a direct bolt-on performance upgrade.

Symptoms Of Wear Or Failure:
Possible symptoms of deteriorating catalytic converters include:

  • Check Engine Light.
  • Catalyst-efficiency fault codes.
  • Reduced engine performance.
  • Slower turbo response.
  • Engine feeling restricted under boost.
  • Reduced high-RPM power.
  • Excessive exhaust backpressure.
  • Metallic rattling from the catalyst.
  • Unusual exhaust smell.
  • Excessive catalyst temperature.
  • Internal catalyst substrate breaking apart.
  • Melted or collapsed catalyst material.
  • Failed emissions testing where applicable.

Catalyst faults should always be correctly diagnosed because a failed catalyst may be the result of another engine problem rather than the original cause.

Why Replacement / Upgrading Matters:
Replacing restrictive or failed catalytic converters with a properly designed high-flow system can help restore or improve:

  • Exhaust gas flow.
  • Turbocharger response.
  • Throttle response.
  • Engine performance.
  • High-RPM breathing.
  • Exhaust sound.
  • Catalyst reliability.
  • Porsche Sport Exhaust functionality.

For performance-modified GT2 RS vehicles, reduced catalyst restriction can also provide greater headroom for additional engine tuning.



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

FSPOR9912GT2RSSC
9P1254400B
9P1254400E
9P1254450B
9P1254450E

The product you are viewing cross references to these numbers
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 5 (of 5 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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