Milltek Large Bore Downpipe Pair & Cats For F80/F82/F83 BMW M3/M4 (Non OPF/GPF)

Fits with Milltek Sport cat back system only - Requires Lambda Extensions

Milltek Large Bore Downpipe Pair with Hi-Flow Sports Catalysts for BMW F80 M3 and F82 M4. Direct bolt-on upgrade fabricated in T304L stainless steel with mandrel-bent construction. Larger diameter than OEM reduces backpressure and increases exhaust scavenging efficiency, delivering measurable performance gains and refined sound character when paired with a Milltek cat-back exhaust system.

Hand-finished T304L stainless construction with CNC-formed flanges and OEM-style hangers. Hi-Flow Sports Catalysts maintain emissions compliance while maximizing flow. Stage 2 ECU remap required for optimal results. Installation requires two lambda sensor extensions (BMW part 18307851168, available from any BMW dealer). Uses factory bolt points—no welding or modification required.

Fitment Details

• BMW F80 M3 (2014-2018) with S55 engine
• BMW F82 M4 (2014-2018) with S55 engine
• Requires Milltek cat-back exhaust system for complete integration
• Not compatible with factory M Performance exhaust

Fits Milltek Cat-Back.

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