CTS Turbo B8/B8.5 Audi A4/A5/AllRoad/Q5 1.8T/2.0T High Flow Catalytic Converter

CTS Turbo B8/B8.5 Audi 1.8T/2.0T High Flow Cat is the premier high flow cat pipe for your Audi A4/A5/Allroad or Q5. Our B8/B8.5 High Flow Cat is designed to seamlessly fit in place of your restrictive stock catalytic converter, which is situated immediately after the turbocharger.  Our B8/B8.5 High Flow Cat features 3" stainless steel piping, smooth mandrel bends, two 02 sensor bungs with an option for a third.  Substantial power gains, improved exhaust flow and a more throaty sound are the main benefits of installing our B8/B8.5 High Flow Cat.  Upon inspection you will notice a flare which is nearly 4", this flare then tapers to 3" and is designed to allow for optimal flow as the exhaust gas transitions from the turbocharger to the B8/B8.5 High Flow Cat.  In addition to being one of the best bang for the buck performance upgrades for A4/A5 owners, our cat pipe is also a very attractive piece.  Each 3" B8/B8.5 High Flow Cat is mandrel-bent, hand tig welded.  Do you need an additional 02 bung for data logging?  Well, that's no problem!  Extra 02 bung is now included at no extra charge. Product Details: - 3" high-flow cat - T304 stainless steel construction - 200 cell stainless steel high flow cat - Mandrel-bent stainless steel - Fully tig welded design - Extra O2 bung for wide-band installation - Install hardware included - Great power upgrade To remove the CEL that will occur, proper tuning software must be used. CTS Turbo recommends choosing a High Flow Cat for the sake of our environment! Use of stage 2 software upgrade is strongly recommended. Fitment for factory turbo, CTS-TR-1070, CTS-TR-1070X and CTS B8 BOSS kits. Fitment:

• 2009 - 2016 Audi A4 2.0T
• 2009 - 2016 Audi A5 2.0T
• 2009 - 2016 Audi AllRoad 2.0T
• 2009 - 2017 Audi Q5 2.0T

• 1.8TFSI EA888 Gen 1 and 2.0TFSI EA888 Gen 2 ONLY!
• Does not fit late ROW cars with EA888 Gen 3 engine.
• Only fits LHD vehicles. Fits manual and automatic transmissions, does not fit CVT.

This part also goes by the following cross reference.

Cross Reference Part Number:

Fits These Vehicles 8 applications

ALLROAD

Make	Model	Engine	Years
AUDI	ALLROAD		2009–2016
AUDI	ALLROAD (B8/8.5)		2009–2016

A4

Make	Model	Engine	Years
AUDI	A4		2009–2016
AUDI	A4 (B8/8.5)		2009–2016

Q5

Make	Model	Engine	Years
AUDI	Q5		2009–2017
AUDI	Q5 (B8/8.5)		2009–2017

A5

Make	Model	Engine	Years
AUDI	A5		2010–2016
AUDI	A5 (B8/8.5)		2010–2016

Fitment data last updated: 2026-06-29