Take the restriction out of your B46 with the OneFastShop 3.5 inch catless downpipe. The factory catalytic converter is the single biggest choke point in the 2.0L turbo exhaust - removing it frees up real power, spools the turbo sooner, and opens up a far more aggressive note. Engineered for US spec B46 powered BMWs and the Toyota GR Supra A91 from 2016 to 2026.
Expect +15 to +27 wheel horsepower with a supporting tune (more on upgraded turbos), faster spool, and sharper throttle response. It's a direct bolt-on with no cutting required, works with OEM and aftermarket cat-back exhausts, and is backed by a lifetime warranty on defects.
| Diameter | 3.5 inch (full diameter from turbo outlet) |
| Material | 304 grade stainless steel, mandrel bent |
| Flanges | CNC machined billet |
| Welding | Hand TIG welded |
| Flex section | Integrated |
| Mounting | Welded bracket included |
| Configuration | Catless (race), catalytic converter removed |
| Engine | BMW B46 (US spec SULEV) and Toyota B46 (Supra A91) |
Engine type: This downpipe fits US spec B46 SULEV engines only. It is not compatible with international market B48 engines, which use a different turbo flange design. Verify your engine code before purchase.
Gasket required: A turbo-to-downpipe gasket is required to seal the downpipe to your factory turbo. Our 4 Inch Turbo to Downpipe Gasket for BMW B46 is sold separately - add one to your order.
Tuning & check engine light: Removing the cat means the rear O2 sensor will eventually set a check engine light (a catalyst efficiency code such as P0420) on an otherwise stock car. This is normal for any catless downpipe and not a fault with the part. To run it correctly and keep the light off, the car should be tuned with the rear O2 sensor turned off - any major B46 / B48 tuning platform supports this. We strongly recommend installing this downpipe with a supporting tune rather than on a stock vehicle.
Off-road use: Intended for off-road and track use only. Not legal for use on public roads and may not comply with emissions regulations. Check local laws before installation.
| Year | Make | Model | Submodel | Engine |
|---|---|---|---|---|
| 2017-2021 | BMW | 2 Series | 230i / 230i xDrive (F22/F23) | B46 |
| 2016-2018 | BMW | 3 Series | 330i / 330i xDrive (F30/F31/F34) | B46 |
| 2019-2024 | BMW | 3 Series | 330i / 330i xDrive (G20/G21) | B46 |
| 2017-2020 | BMW | 4 Series | 430i / 430i xDrive (F32/F33/F36) | B46 |
| 2021-2024 | BMW | 4 Series | 430i / 430i xDrive (G22/G23/G26) | B46 |
| 2017-2023 | BMW | 5 Series | 530i / 530i xDrive (G30) | B46 |
| 2018-2024 | BMW | X3 | xDrive30i (G01) | B46 |
| 2018-2024 | BMW | X4 | xDrive30i (G02) | B46 |
| 2019-2024 | BMW | Z4 | sDrive30i (G29) | B46 |
| 2022-2026 | Toyota | Supra | A91 2.0 | B46 |
