OEM catalysts are often very dense and restrictive to gas flow. These pipes de-restrict airflow, resulting in a louder exhaust note and improved performance. All performance exhaust systems are designed for a wide range of vehicles. The research and development team works throughout the year to deliver solutions for performance exhaust requirements. All products are made in the UK and distributed to over 90 countries worldwide. Note: Requires a Stage 2 ECU remap. Note: Fits only with Milltek Sport Cat Back (lambda cables need extending). - De-restricts airflow for improved performance - Designed for a louder exhaust experience - Made in the UK and distributed globally Specifications: - Pipe Diameter: 70.00 - Race Product: Yes - EMarked: No Kit comes with: - MSAU636REP: LH Catalyst Bypass Pipe (under-floor) - MSAU637REP: RH Catalyst Bypass Pipe (under-floor) - MSAU663: LH 76mm Primary Cat Bypass Downpipe (fits LH Turbo) - MSAU663 - MSAU664: RH 76mm Primary Cat Bypass Downpipe (fits RH Turbo) - MSAU664 Vehicle Compatibility: - 2013-2018 Audi S8 D4 4.0 TFSI quattro Tiptronic