For over 30 years, Active Autowerke has built BMW performance hardware that works without compromise. These S68T Aflow downpipes bring the same engineering to the G90 M5 at a lower entry point than the GESI version, without giving up the no-CEL guarantee or the bolt-on install.
Manufactured in-house in Miami, Florida from 304 stainless steel and TIG-welded throughout, each downpipe uses a cast upper stainless V-band for precise fitment, then runs a factory-matched offset inlet into a 3” mandrel-bent body. The lower mid-pipe section is included, and the assembly accepts the OEM O2 sensor heat shield for a factory-appearing engine bay.
A pair of 5” Active Aflow high-flow catalytic converters carries a 400 cell per square inch substrate that reaches operating efficiency within 9 seconds of startup. EPA registered and OBD2 compliant in 49 states, with no CEL for catalytic efficiency and no performance tune required.
Key Features
- No CEL for catalytic efficiency, guaranteed
- 5” Active Aflow high-flow cats, EPA registered and OBD2 compliant
- 400 cpsi ultra high-flow substrate, furnace-brazed to a 304 stainless mantle
- Cast upper stainless steel V-band for precise fitment
- 3” mandrel-bent piping with factory-matched offset inlet
- Includes the lower mid-pipe section
- Quicker turbo spool and sharper throttle response
- No performance tune needed
- 304 stainless steel with TIG-welded construction
- Direct bolt-on fit, no cutting or welding
- Accepts OEM O2 sensor heat shield for a sleeper look
- Rated for up to 1,000 HP applications
- Withstands up to 1500°F
- Reaches operating efficiency within 9 seconds of startup
- Made in Miami, Florida
- 5-Year / 50,000-Mile Warranty on shell and tube ends, 2-Year / 25,000-Mile Warranty on catalytic core
Vehicle Fitment
BMW M5 (G90), 2025 and newer, and M5 Touring (G99)
Not legal for sale or use on pollution-controlled motor vehicles registered in California per California Vehicle Code sections 27156 and 38391. Warranty on the catalytic core is void if the vehicle produces burble or overrun fueling in excess of stock, which physically destroys the catalyst.
