The part is used to bypass the catalyst from the exhaust to create a decat system. Eliminating the catalyst greatly enhances gas flow and performance, adding significant horsepower by removing the density of the catalyst through which exhaust gases are pushed. This product is intended for motorsport use only and requires a Stage 2 ECU remap. - Bypasses the catalyst for increased exhaust flow - Designed to enhance vehicle performance - Motorsport use only; not E-marked - Manufactured in the UK and distributed worldwide Specifications: - Pipe Diameter: 63.50 - Installation Time: 1 to 1.5 hours (including removing OE system) - Race Product: Yes - E-marked: No Vehicle Compatibility: - Audi A6 55 TFSI (3.0 V6 Turbo) C8 2019 and later - Audi A7 55 TFSI (3.0 V6 Turbo) C8 2019 and later - Audi S4 3.0 Turbo V6 B9 Saloon/Sedan & Avant (Non Sport Diff Models) Left Hand Drive 2016 and later - Audi S4 3.0 Turbo V6 B9 Saloon/Sedan & Avant (Non Sport Diff Models) Right Hand Drive 2016 and later - Audi S4 3.0 Turbo V6 B9 Saloon/Sedan & Avant (Sport Diff Models Only & Without Brace Bars) Left Hand Drive 2016 and later - Audi S4 3.0 Turbo V6 B9 Saloon/Sedan & Avant (Sport Diff Models Only & Without Brace Bars) Right Hand Drive 2016 and later - Audi S5 3.0 V6 Turbo Coupe Only B9 (Sport Diff Models Only & WITH Brace Bars) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Coupe Only B9 (Sport Diff Models Only & WITH Brace Bars) Right Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Coupe Only B9 (Sport Diff Models Only & Without Brace Bars) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Coupe Only B9 (Sport Diff Models Only & Without Brace Bars) Right Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Coupe/Cabrio B9 (Non Sport Diff Models Only) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Coupe/Cabrio B9 (Non Sport Diff Models Only) Right Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Non Sport Diff Models Only) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Non Sport Diff Models Only) Right Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Sport Diff Models Only & WITH Brace Bars) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Sport Diff Models Only & WITH Brace Bars) Right Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Sport Diff Models Only & without Brace Bars) Left Hand Drive 2017 and later - Audi S5 3.0 V6 Turbo Sportback B9 (Sport Diff Models Only & without Brace Bars) Right Hand Drive 2017 and later