Description
Take your BMW B58-powered vehicle or Toyota Supra to the next level with the MAD 5" B58 300 Cell Catted Downpipe. Engineered for enthusiasts seeking increased horsepower, improved throttle response, enhanced exhaust flow, and a more aggressive exhaust note, this premium performance downpipe delivers outstanding results while maintaining everyday drivability.
Manufactured from high-quality 304 stainless steel, the MAD B58 Catted Downpipe is built to withstand extreme temperatures and demanding driving conditions. Its large 5-inch design and smooth mandrel-bent construction maximize exhaust flow while minimizing restriction and back pressure, allowing your turbocharged engine to perform at its full potential.
The integrated 300-cell high-flow catalytic converter provides exceptional flow characteristics while helping reduce exhaust restrictions. Combined with the precision-engineered design, drivers can experience gains of up to 30 horsepower on stock turbochargers, with even greater potential when paired with upgraded turbo systems.
One of the standout features of this downpipe is MAD's No CEL Guarantee. If a check engine light related to catalytic converter efficiency occurs during the warranty period, MAD will replace the downpipe free of charge, providing added confidence and reliability.
Designed as a direct bolt-on replacement for the factory downpipe, installation requires no cutting or welding. The included flex section improves durability and helps absorb engine movement, while compatibility with both factory and aftermarket exhaust systems allows for maximum customization.
Features
- Large 5-inch high-flow downpipe design
- Premium 304 stainless steel construction
- 300-cell high-flow catalytic converter
- No CEL Guarantee
- Free replacement if a catalytic-converter-related CEL occurs during the warranty period
- Direct bolt-on installation
- No cutting or welding required
- Compatible with factory and aftermarket exhaust systems
- Integrated flex section for durability
- Compatible with left-hand drive and right-hand drive vehicles
- Smooth bends for maximum airflow
- Designed to minimize drone
- Gains of up to 30 horsepower on stock turbochargers
- Supports even greater gains with upgraded turbo systems
- Lifetime warranty on the downpipe
- 2-year warranty on the catalytic converter
- Ships within 1-2 business days
- Race-use performance design
Warranty Information
- No CEL Guarantee valid for 2 years from the original purchase date
- Free replacement if a catalytic-converter-related check engine light occurs during the warranty period
- Lifetime warranty against manufacturer defects, including cracks in the pipe or welds
- 2-year warranty coverage on the catalytic converter
Important Installation Note
- Downpipe gasket is not included
- BMW Gasket Part Number Required: 18328612538
Vehicle Fitment
- 2015+ BMW M240i
- 2015+ BMW M240i xDrive
- 2016-2019 BMW 340i
- 2016-2019 BMW 340i xDrive
- 2020-2024 BMW M340i
- 2020-2024 BMW M340i xDrive
- Does NOT fit 2025+ BMW M340i models
- 2016+ BMW 440i
- 2016+ BMW 440i xDrive
- 2016+ BMW 540i
- 2016+ BMW 540i xDrive
- 2016-2020 BMW 640i Gran Turismo (G32)
- 2016-2020 BMW 640i Gran Turismo xDrive (G32)
- 2016+ BMW 740i
- 2016+ BMW 740i xDrive
- 2017-2024 BMW X3 M40i (G01/G02)
- 2017-2024 BMW X4 M40i (G01/G02)
- 2019-2022 BMW X5 40i (G05, Non-LCI Only)
- 2019-2022 BMW X5 xDrive40i (G05, Non-LCI Only)
- 2018-2022 BMW X6 40i (G06, Non-LCI Only)
- 2018-2022 BMW X6 xDrive40i (G06, Non-LCI Only)
- 2019+ BMW X7 40i (G07, Non-LCI Only)
- 2019+ BMW X7 xDrive40i (G07, Non-LCI Only)
- 2019+ BMW Z4 M40i (G29)
- 2019+ Toyota Supra 3.0L
Emissions Disclaimer
Race Use Only
This product is not legal for sale or use on pollution-controlled motor vehicles operated on public roads, highways, or streets. It is intended solely for off-road, racing, or closed-course competition vehicles where such modifications are permitted by law.
By purchasing and installing this product, you acknowledge and agree that:
- You are responsible for compliance with all applicable federal, state, provincial, and local emissions laws and regulations.
- MAD and its affiliates disclaim all liability for improper, unlawful, or unintended use of this product.
- Use of this product on public roads may violate the Federal Clean Air Act (42 U.S.C. § 7522) and similar state or local laws.
- It is the purchaser's responsibility to verify compliance with local regulations before purchase and installation.
