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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 5 (of 5 products)
CARP44S2NGT_KIT
Product Information
Product Information
Sports exhaust system manifold back with catalytic converter. Porsche 944 S2

cargraphic

Fits:
Porsche 944 S2 3.0L WITH catalytic converter
Engine Code M44-41


Product description:

CARGRAPHIC N-GT Sport Exhaust System Manifold Back SS304L - Homologated for N-GT class

Consisting of:
• CARGRAPHIC Downpipe with 100cpsi Ø130mm MOTORSPORT catalytic converter and pre-silencer with 2,25"/57,15mm pipework
• CARGRAPHIC Sport center silencer
• CARGRAPHIC Sport rear silencer
• CARGRAPHIC Sport tailpipe 115x85mm oval, slash cut, double wall with perforated insert - Mirror polished

NO DRONE OR RESONATION even in combination with other CARGRAPHIC exhaust components fitted.

Features:

• Specially designed and homologated for N-GT class reglement
• All parts are interchangeable with factory / OE parts
• Absorptive silencer design with CNC mandrel-bent pipework
• Fully made from SS304L lightweight stainless stee
• High performance components, dyno tested
• Reinforced laser-cut brackets
• Reduced backpressure due to freer flowing
• Reduced operating temperature
• Maximized performance
• Improved throttle response, freer revving
• Improved enhanced acoustics with no drone, resonation or vibration
• Model specific tuned sound still in keeping with the Marque
• Weight reduction

PERFORMANCE - Made in Germany

up to 7KW (10PS) more power and 10Nm additional torque
FSPOR944TCBD
Product Information
Product Information
Fabspeed Catbypass pipe and downtube.

fabspeed

Increase exhaust flow from the headers to the mufflers and improving power and sound by replacing the catalytic converters with straight-through pipes.

FEATURES:
Fits all Porsche 944 Turbo 951 vehicles (1985-1991)
• Increases horsepower and torque by 26 whp and 29 ft-lbs
• Constructed from CNC mandrel-bent T304L stainless steel
• Direct replacement for the factory catalytic converters
• Bolt-on installation
• All Fabspeed performance products are backed by the Fabspeed Lifetime Limited Warranty

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.

FSPOR944TCBD
95111109304
95111109411
95111109412

The product you are viewing cross references to these numbers
CARP44DPVSDER
Product Information
Product Information
Downpipe and Front Silencer delete pipe for - Porsche 944 2.7ltr M44-11 and M44-12 CARGRAPHIC N-GT

cargraphic

Fits:
Porsche 944 2.7L 1988 - 1989
Engine Codes - M44-11 and M44.12

Product description:
Downpipe with Pre-Silencer delete pipe SS304L

NO DRONE OR RESONATION even in combination with other CARGRAPHIC exhaust components fitted.

Features:

• All parts are interchangeable with factory / OE parts
• Absorptive silencer design with CNC mandrel-bent pipework
• Fully made from SS304L lightweight stainless steel
• High performance components, dyno tested
• Reinforced laser-cut brackets
• Reduced backpressure due to freer flowing
• Reduced operating temperature
• Maximized performance
• Improved throttle response, freer revving
• Improved enhanced acoustics with no drone, resonation or vibration
• Model specific tuned sound still in keeping with the Marque
• Weight reduction

PERFORMANCE - Made in Germany

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

CARP44DPVSDER
94411198703
94411198503
94411198501

The product you are viewing cross references to these numbers
CARP44S2NGT1
Product Information
Product Information
Downpipe with catalytic converter for - Porsche 944 S2 3.0L M44-41 CARGRAPHIC N-GT

cargraphic

Fits:
Porsche 944 S2 3.0L 1989 - 1991
Engine Code - M44-41

Product description
CARGRAPHIC N-GT Sport Downpipe Manifold Back SS304L - Homologated for N-GT class

Consisting of:
• CARGRAPHIC Downpipe with 100cpsi Ø130mm MOTORSPORT catalytic converter and pre-silencer with 2,25"/57,15mm pipework

NO DRONE OR RESONATION even in combination with other CARGRAPHIC exhaust components fitted.

Features:

• All parts are interchangeable with factory / OE parts
• Absorptive silencer design with CNC mandrel-bent pipework
• Fully made from SS304L lightweight stainless steel
• High performance components, dyno tested
• Reinforced laser-cut brackets
• Reduced backpressure due to freer flowing
• Reduced operating temperature
• Maximized performance
• Improved throttle response, freer revving
• Improved enhanced acoustics with no drone, resonation or vibration
• Model specific tuned sound still in keeping with the Marque
• Weight reduction

PERFORMANCE - Made in Germany

up to 7KW (10PS) more power and 10Nm additional torque

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

CARP44S2NGT1
94411198907
94411198101

The product you are viewing cross references to these numbers
94411198904/1
Product Information
Product Information
Exhaust catalytic converter.

designtek

Fits:
PORSCHE 944S 2.5i (M44.40 engine) 1/86-7/88
PORSCHE 944S2 3.0i (M44.41 engine) 8/88-7/92

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.

94411198904
94411198904

The product you are viewing cross references to these numbers
DISPLAYING 1 to 5 (of 5 products)
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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