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Design 911 Design 911 supply Porsche parts, Porsche spares and Porsche accessories, to both retail and to the trade. Our Porsche product and accessory range includes brakes, exhausts, tyres, wheels and Porsche panels and interiors. https://www.design91.uk/images/schemaLogo.png https://www.design91.uk/images/schemaLogo.png +443456003478 https://www.design91.uk Facebook Instagram

Catalyst / Bypass

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DISPLAYING 1 to 7 (of 7 products)
Special Order item
99311324751
Product Information
Product Information
Exhaust Cat centre heat shield. Replacement centre heat shield for Cat.

porsche

Fits:
Porsche 993 Turbo 1994-98

Click 'Zoom in' for large parts diagram.
Diagram Ref No 19

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99311324751
99311324751

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Special Order item
99311324351
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Exhaust Cat Heat shield Left
porsche

Replacement heat sheild left for Cat.

Fits:
Porsche 993 Turbo 1994-98

Diagram Ref No 34
Special Order item
99311324451
Product Information
Product Information
Exhaust Cat Heat shield Right
porsche

Replacement heat sheild right for Cat.

Fits:
Porsche 993 Turbo 1994-98

Diagram Ref No 23
96511120500/1
Product Information
Product Information
Exhaust sealing ring turbo to catalytic converter. 
Price is for each

oematch

Fits:
Porsche 993 turbo - 1994 to 1997

Click 'Zoom in' for large parts diagram.
Diagram ref no 3



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Related, superseded, cross reference or alternative numbers for comparison.

96511120500
96411120500
96511120500

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FSPOR993TSCX
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Product Information
Exhaust Sport Cat X- Pipe.
High performance free-flowing X-Pipe replaces the heavy and restrictive factory muffler for improved power and sound.

fabspeed

Please note:
This product is currently undergoing a design update and will be available for purchase soon. Please contact us for details.


FEATURES:
Fits all Porsche 993 Turbo / Turbo S vehicles (1995-1998)
• Improves power and throttle response
• Saves 8 lbs from the rear of the vehicle
• Constructed from high-quality 14-16 gauge C.N.C. mandrel-bent T304L stainless steel for optimum flow and maximum durability
• Direct bolt-on replacement for restrictive factory muffler
• All Fabspeed performance products are backed by the Fabspeed Lifetime Limited Warranty

NOTE: Fabspeed's 200-cell high-flow catalytic converters are not C.A.R.B. certified and are for Off-Road Use ONLY in the state of California

Please note: This is a special-order item manufactured to order. In some cases, please allow 4 – 5 weeks for the delivery. Special order items cannot be cancelled from this supplier once your order has been placed.

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.

FSPOR993TSCX
99311321357
99311221358
99311321359
99311321457
99311321458
99311321459

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

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FSPOR993TCBX
Product Information
Product Information
Fabspeed Modular cat bypass x-pipe Competition ONLY.

fabspeed

Replaces the restrictive factory catalytic converters with much less restrictive straight-through pipes for maximum flow and performance.

FEATURES:

Fits all Porsche 993 Turbo / Turbo S vehicles worldwide (1995-1998)
• Fabspeed's Primary Catbypass Pipes replace the restrictive factory catalytic converters with much less restrictive straight-through pipes for maximum flow and performance.
• Noticeable increase in power and improved throttle response
• Saves 12 lbs from the rear of the vehicle
• Adds an aggressive exhaust note for exotic high-performance sound
• Direct bolt-on replacement for the heavy factory catalytic converters on the 993 Turbo
• Constructed from polished T304L stainless steel
• Optional 02 spacers available to help prevent triggering the Check Engine Light
• All Fabspeed performance products are backed by the Fabspeed Lifetime Warranty

DISCLAIMER: This product removes the OEM intake filter system from the vehicle, and as such, is strictly intended for closed track events and off-road use only. This product contains a High-Flow Air Filter solely intended for track and race cars as it is NOT California Air Resources Board Certified (CARB) and not EPA certified. You are hereby informed and warned to check your local, state, and federal laws before buying and installing these or any aftermarket parts to be sure whether usage is in violation. All installation-risk and use-risk is borne by the end-user and installer of these parts.

DISCLAIMER: This product removes the OEM catalytic converters from the vehicle, and as such, is strictly intended for closed track events and off-road use only, never to be driven on public roads. This product is or contains a Racing Cat Bypass Pipe, which will give you check engine lights on OBD2 cars. Racing Cat Bypass Pipes are solely intended for track and race cars as they are NOT California Air Resources Board Certified (CARB) and not EPA certified. You are hereby informed and warned to check your local, state, and federal laws before buying and installing these or any aftermarket parts to be sure whether usage is in violation. All installation-risk and use-risk is borne by the end-user and installer of these parts.

Please note: This is a special-order item manufactured to order. In some cases, please allow 4 – 5 weeks for the delivery. Special order items cannot be cancelled from this supplier once your order has been placed.

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.

FSPOR993TCBX
99311321357
99311221358
99311321359
99311321457
99311321458
99311321459

The product you are viewing cross references to these numbers
DISPLAYING 1 to 7 (of 7 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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