Bull-X downpipe for Audi A4/A5 B9 2.0 TFSI with ECE approval

BULL-X Exhausts produces high-quality downpipes. This downpipe for the Audi A4/A5 B9 2.0 TFSI from HG Motorsport can be used as a complete replacement for the standard part. Precise fitment and high-quality materials ensure reliable installation. Optimising the diameter, pipe routing and catalytic converter significantly reduces the load on the turbocharger. Lower back pressure and reduced thermal load provide increased torque, more power and sharper engine response, while potentially extending service life.

Technical details

• Pipe diameter: 89 mm/3.5″ up to the catalytic converter inlet (standard: 76 mm)
• 76 mm/3″ from the catalytic converter outlet onwards (standard: 63 mm)
• Made from stainless steel
• Fully TIG welded
• Available without a catalytic converter, with a 100-cell sports catalytic converter, with a 200-cell sports catalytic converter, with a Bull-X 200-cell EOBD sports catalytic converter by HJS, or with a 200-cell HJS sports catalytic converter with ECE approval (standard: 600 cells)
• Plug’n’Play solution
• Precise fitment and simple replacement of the original part
• High-quality materials
• Made in Germany
• Flow-optimised for increased performance
• Improved durability and engine response
• Optimal evacuation of exhaust gases
• No disruptive edges at the transitions
• Designed and tested using computer simulations and on a dynamometer
• No more heat build-up at the turbocharger, reducing thermal load
• Sharper response and a measurable, slight increase in power
• More pronounced exhaust sound
• 89 mm diameter directly from the turbocharger outlet without a step; 76 mm from the catalytic converter outlet to the flange

Road use: Only the version with the 200-cell HJS sports catalytic converter with ECE approval is approved for use on public roads. Versions without a catalytic converter, and versions with 100- or 200-cell sports catalytic converters without ECE approval, are intended exclusively for track use.

Catalytic converter information

When selecting a downpipe without a catalytic converter or with a 100- or 200-cell catalytic converter, the engine control unit may display a fault from the post-catalytic-converter lambda sensor. This does not affect driving, as the first lambda sensor remains in place for engine management, while the post-catalytic-converter sensor only monitors catalytic converter efficiency. The fault can be removed by adapting the software through a specialist engine calibration provider.

Most vehicles with an emissions standard up to Euro 3 do not have a post-catalytic-converter lambda sensor, so installation is possible without further adaptation or a fault message. HJS ECE and EOBD catalytic converters have a significantly higher washcoat content and very high oxygen-storage capacity, which can prevent fault messages. The EOBD catalytic converters have been tested for this purpose up to Euro 4, while their durability and use are suitable up to Euro 6. On Euro 5/6 vehicles, the points above can only be avoided by selecting a version with an ECE catalytic converter.

Suitable for: Audi A4 IV (B9), Audi A5 II (F5/F53).

Manufacturer’s vehicle data

• Bull-X Downpipe Audi A4/A5 B9 2.0 TFSI (mit ECE*)

Original product name by HG Motorsport (»z.B.« = e.g.). Please check model, year and engine of your vehicle before ordering; if in doubt, contact us and we will check for you.

Approval

Only the version marked “road legal” has a European ECE / EC approval (Bull-X Tronic controller with ECE or the HJS EC catalytic converter). Versions marked “no ECE, track use only” have no approval and are not permitted for road use. If in doubt about the version, contact us and we will check for you.