CTS Turbo B5 Audi A4 High Flow Cat

CTS Turbo's B5 A4 1.8T High Flow Cat Pipe is the go-to cat upgrade for your Audi. It drops straight into the spot of the restrictive stock catalytic converter, which sits immediately after the turbocharger.

The pipe runs 3" stainless steel with smooth mandrel bends and two O2 sensor bungs, with the option to add a third. You get substantial power gains, better exhaust flow, and a throatier sound. Look closely and you'll see a flare near 4" that tapers to 3", designed to optimize flow as exhaust gas transitions from the turbo into the pipe. It's one of the best bang-for-buck upgrades for A4 owners, and it looks the part too. Each 3" pipe is mandrel-bent and hand TIG welded.

Fitment

• 1997-2001 B5 Audi A4 1.8T

Product details

• T304 stainless steel construction
• Mandrel-bent stainless steel
• Fully TIG welded design
• Optional third O2 bung available
• Install hardware included

To clear the CEL that will occur, proper tuning software must be used — Stage 2 software is strongly recommended.

Emissions disclaimer: This product is not legal for sale or use on pollution-controlled vehicles operated on public roads and is intended for off-road, race, or closed-course competition use only. You are responsible for compliance with all applicable emissions laws; use on public roads may violate the Federal Clean Air Act (42 U.S.C. § 7522) and similar state laws. Please check your local laws before purchase and installation.

Ships from our Vancouver shop — KORE SPEED is proudly Canadian-owned, with no surprise cross-border duties for Canadian buyers. Questions on fitment? Email support@korespeed.com.