CTS Turbo 2018+ B9 Audi S4/S5 V6T 3.0T (EA839) HIGH-FLOW CAT

CTS Turbo B9 S4/S5 3.0T (EA839) high flow cat is made to maximize exhaust flow for highest power gains. Do not compromise performance and sound with factory parts - unleash your B9 S4/S5 3.0T potential! Designed using the latest in CAD technology; this part is made to fit perfectly in place of restrictive factory catalytic converter. Manufactured from cast T304 stainless steel, hand TIG welded and back-purged to ensure years of reliable performance. In addition to unleashing the power and performance of your 3.0T, the CTS B9 S4/S5 3.0T EA839 high flow cat will make your vehicle sound like an S-car really should. When installed with factory exhaust it produces a sporty growl with much more pronounced exhaust "crackle" on downshift. While up-shifting you will enjoy a confident "braappp!" as you bang through all 8 gears. The sound will be even louder if you already have an aftermarket exhaust system. Product Details:

• Designed and tested on a real car in the real world
• 200 cell steel high-flow race cat
• Cast stainless steel body
• Replaces restrictive factory catalytic converter
• Great power upgrade with uncompromising performance
• Incredible sporty exhaust sound, subtle when cruising
• No drone with factory exhaust
• Install hardware included

Fitment:

• 2018+ Audi S4 3.oT (EA839)
• 2018+ Audi S5 3.oT (EA839)

To remove the CEL that will occur, proper tuning software must be used.

This part also goes by the following cross reference.

Cross Reference Part Number:

Fits These Vehicles 2 applications

S4

Make	Model	Engine	Years
AUDI	S4 (B9)		2018–2021

S5

Make	Model	Engine	Years
AUDI	S5 (B9)		2018–2021

Fitment data last updated: 2026-10-01

✓ Fits 2 vehicle applications Check vehicle fitment before ordering View fitment