MST 6" Catted Downpipe – BMW / Toyota B58 3.0T

Engineered for maximum performance, the MST 6" catted downpipe is one of the highest-efficiency solutions available for B58-powered BMW and Toyota vehicles. Built with a Euro 6 400-cell catalytic converter, this large-diameter downpipe delivers the flow of a straight pipe—without triggering check engine lights. Perfect for both stock and high-powered builds, it enhances throttle response, exhaust tone, and overall power delivery.

Features
• Largest diameter B58 downpipe on the market
• Euro 6 400-cell catalytic converter – 6" design
• No CEL guarantee
• Same efficiency as straight pipe, with cleaner emissions
• CNC turbo adapter matched to large-diameter turbos
• Dyno-tested gains: +18–25hp / +4kgm torque (on stock vehicle)
• Supports 1000+hp builds
• Dramatically lowers exhaust pressure and temps
• Suitable for both GPF and non-GPF vehicles
• Compatible with stock and tuned setups

Vehicle Compatibility
• BMW M140i (F20, 2016+)
• BMW M240i / M240i xDrive (F22, G42)
• BMW 340i / 340i xDrive (F30/F31, G20)
• BMW 440i / 440i xDrive (F32/F33/F36, G22/G23/G26)
• BMW 540i / 540i xDrive (G30/G31)
• BMW 740i / 740i xDrive (G11/G12)
• Toyota GR Supra A90 / A91 (2019+)