Milltek Weld-In High-Flow Sports Catalyst- 100CPSI- 76.2mm Cone Sticker 2018 - Present Audi S4

2018 - Present Audi S4 (B9)

Fingerprint & Dust Resistant

and other limitations found with standard plugs

The HJS tuning ECE Downpipes are specifically designed to be fully road legal within Europe (R103 compliant) while still providing the benefits of the High Flow Sports Cat

Black Cap & Red Peak

Milltek Weld-In High-Flow Sports Catalyst- 100CPSI- 76.2mm Cone Sticker 2018 - Present Audi S4Your original catalytic converter will typically have 400 or 600 Cells per square inch (CPSI) these original cats are restrictive in their flow typically allowing an open area of around 55 65% Milltek Sport Hi Flow Sports Cat which will be fully integrated into a large bore downpipe has only 100 200 CPSI depending on application These cats have an open area of between 75 85% thus reducing back pressure substantially and increasing flow rates all very