Choosing a Milltek exhaust for the G20 and G21 M340i
UK and European M340i xDrive saloons and Touring models with an OPF/GPF (pre-LCI, 2019-25) have the widest choice: a filter-back system, a cat-back, Active Valve Control, HJS Tuning ECE downpipes, a sports cat downpipe and a de-cat downpipe. North American and rest-of-world G20 saloons (2021-25, including xDrive) have their own cat-back and a choice of sports cat or de-cat downpipe. The two markets are listed separately, so check whether your car has a particulate filter.
One earlier listing, HJS ECE downpipes titled M340i for 2017-19 saloons and Touring models, xDrive or not, predates the G20. Check its fitment details or use the reg lookup to confirm it suits your car before ordering.
320i, 328i and E36 3 Series exhausts
For the F30 320i M Sport saloon LCI (B48, non-xDrive, 2015-19), Milltek has a cat-back, plus a separate version for the long-wheelbase 320i L. The F30 328i M Sport automatic (N20, non-xDrive, 2012-15, no tow bar) has a cat-back and a de-cat downpipe. Classic owners get a single E36 325i and 328i cat-back for 1991-99 cars.
Downpipes and catalysts for the 3 Series
HJS ECE downpipes and sports cat downpipes keep a catalyst in the system; de-cat downpipes are for off-road and competition use only and will fail an MOT emissions test. Most downpipe upgrades need an ECU remap. Resonated cat-backs are the quieter choice with less drone, and one resonated version is listed as EC approved. Browse manifolds, de-cats and sports cats for more, the BMW M3 collection if you drive the M car, or the 4 Series collection for the M440i coupé.
Buying from Milltek Exhaust Shop for your 3 Series
Not sure whether your M340i has a particulate filter? Enter your reg in the lookup at the top of the page and the list trims down to parts that match. We offer free UK delivery, worldwide shipping, Klarna and PayPal, and fitting at our Stoke-on-Trent workshop.