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BMW S58 downpipe guide: G80 M3, G82 M4 and the OPF question
August 26, 2026 · OKTAN
The S58 is BMW's current M straight-six — brutally capable and very tunable. A downpipe or high-flow sport cats free up its most restrictive section.
The OPF / GPF consideration
Many S58 cars ship with a petrol particulate filter (OPF/GPF) in addition to the primary cats. A downpipe targets the restrictive primary catalyst at the turbo; if your car has an OPF, factor that into your emissions and legality choices. Catless setups are strictly off-road / competition use.
Downpipe or sport cats?
Choose a catless downpipe for maximum flow (off-road), or 200-cell high-flow sport cats to stay far more street-friendly while still opening the engine up.
What fits
Fits the M3 (G80), M4 (G82/G83), M2 (G87), X3 M (F97) and X4 M (F98).