Milltek Hi-Flow Sports Cat - Audi RS3 8V - SSXAU771

ECE-approved hi-flow sports cat designed for European road use (R103 compliant). T304L stainless steel construction with 200–300 cell density provides unrestricted exhaust flow without requiring ECU recalibration or triggering diagnostic codes. Direct fitment with OEM cat-back systems and Milltek cat-back exhausts.

Hand-finished T304L stainless steel core with CNC-formed housings. EC Type Approval ensures full street legality across Europe. No software modifications required—bolt-on installation using existing hangers and O2 sensor locations.

Fitment:

• Compatible with OEM factory cat-back systems
• Compatible with Milltek cat-back exhaust systems
• Retains OE oxygen sensor and diagnostics
• No ECU tune or check engine light risk

Engineered for sustained flow and reliability on both road and circuit.

Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Specifications

• Pipe diameter: 63.55mm (2.50")
• Fitting time: 3 to 3.5 hours, including removing the factory system
• E-marked for road use

Fitment

• Audi > RS3 > Saloon/Sedan (8V MQB) > 2017 and Later
• Audi > TT MK3 > TTRS 2.5TFSI Quattro > 2016 and Later

• Free US shipping on orders over $250.
• Free pickup at our Dallas shop, usually ready within 24 hours.
• Unused parts can be returned within 30 days. Tunes, opened electronics, merch and installed parts are final sale.
• Want it installed? Book the install at thegbmotors.com.

Full details are on our shipping and returns page.