Active Autowerke G20 M340i/G22 M440i B58N AFlow Downpipe

The Active Autowerke B58N AFlow catted downpipe is for the 2025+ BMW G20 M340i and G22/G23/G26 M440i with the Gen 3 B58N engine. On these cars BMW added a gasoline particulate filter (GPF) to the factory downpipe, and this pipe replaces that unit with a far freer-flowing design.

Active Autowerke notes that removing the stock GPF downpipe takes about 9 to 10 hours of labor, because the subframe has to be dropped.

The Active Autowerke AFlow catted downpipe for the BMW M340i G20 and M440i G22 2025+ delivers a measurable improvement in exhaust flow and turbo response while remaining fully OBD2 compliant with no check engine light. The Active AFlow high flow catalyst uses advanced substrate technology to maximize flow while keeping emissions within OBD2 thresholds. Paired with 304 stainless steel mandrel-bent piping, this is a bolt-on upgrade that improves throttle response, reduces turbo lag, and adds a more aggressive exhaust note — all without triggering a CEL. OBD2 compliant — no check engine light (CEL)

What It Does

The downpipe uses 5 in stainless piping for more power, quicker spool and durability, tapering to a stainless flex joint and then down to 80 mm to meet the factory exhaust. Active Autowerke never drops below the stock 80 mm diameter. A 5 in Active Autowerke AFlow high-flow cat with a 400 cpsi substrate is built in.

Materials and Construction

TIG-welded 304 stainless steel with 1.5 mm wall thickness and a cast stainless upper V-band for a precise fit. It bolts on with no cutting or welding, and the turbo flange gasket is included.

Features

• For 2025+ B58N cars with the factory GPF downpipe
• 5 in piping to 80 mm
• 5 in AFlow high-flow cat, 400 cpsi
• Cast stainless upper V-band
• Turbo flange gasket included

Specs

• Part number: 11-062GA
• Brand: Active Autowerke
• Type: catted downpipe
• Catalyst: Active Autowerke AFlow, 5 in, 400 cpsi
• Piping: 5 in to 80 mm
• Wall thickness: 1.5 mm
• Engine: BMW B58N (Gen 3) 3.0L turbo inline-six
• Shipping weight (Active Autowerke): 35 lb (15.9 kg)

Fitment Notes

• Plan for 9-10 hours of labor: the subframe must be dropped to remove the GPF downpipe.
• For 2024 and older cars, use the Active Autowerke B58 downpipe.
• Active Autowerke fitment applies to US-model cars only.
• Active Autowerke covers the shell and tube ends for 5 years / 50,000 miles and the catalyst core for 2 years / 25,000 miles for the original buyer. Excessive burble (more than stock) voids the warranty because it destroys the catalyst core.
• Questions before you order? Call or text (310) 231-0292 or email Online@AutoTalent.com.
• Shop all Active Autowerke downpipes, B58 downpipes, every catted downpipe we carry, or the full Active Autowerke range.

FAQ

Does it fit my 2023 M340i?
No. 2024 and older cars use the Active Autowerke B58 downpipe.

How long is the install?
About 9 to 10 hours, since the subframe has to come down.

GESI or AFlow?
GESI uses GESI cats; AFlow uses Active Autowerke's own cats at a lower price.