B58 4.5-Inch Heat-Shielded Catless Downpipe

Developed for compatible B58 applications, this catless downpipe replaces the restrictive factory primary catalytic converter with a straight-through exhaust path. The freer-flowing design reduces post-turbine backpressure, supporting quicker turbo response, increased performance potential, and a louder, more aggressive B58 exhaust note.

The downpipe is manufactured from 304 stainless steel and enclosed by a thermal insulation layer that helps reduce radiant heat transfer to nearby engine-bay components. Factory-style oxygen-sensor ports support installation on compatible vehicles.

Common B58 Applications

• Toyota GR Supra A90/A91 3.0 B58 - 2019+.
• BMW M240i / M240i xDrive - F22, F23, and G42 B58 models.
• BMW 340i / M340i and xDrive - F30, F31, F34, G20, and G21 B58 models.
• BMW 440i / M440i and xDrive - F32, F33, F36, G22, G23, and G26 B58 models.
• BMW 540i / 540i xDrive - G30 and G31 B58 models.
• BMW 740i / 740i xDrive - G11 and G12 B58 models.
• BMW X3 M40i / X4 M40i - G01 and G02 B58 models.
• BMW Z4 M40i - G29 B58 models.

Features

• Straight-through catless design.
• Integrated thermal insulation layer helps reduce radiant heat.
• 304 stainless-steel construction.
• Factory-style oxygen-sensor ports.
• Reduced exhaust restriction and post-turbine backpressure.
• Quicker turbo response.
• More pronounced turbo and exhaust sound.

Important Notes

FOR CLOSED-COURSE COMPETITION / TRACK USE ONLY.

This product removes the primary catalytic converter and is not intended for public-road use where emissions equipment removal is prohibited.

A catalyst-efficiency warning light is likely without compatible ECU calibration; suitable tuning is recommended.

Fitment can vary by B58 generation, production year, emissions specification, and GPF/OPF configuration.

Confirm the VIN, turbo outlet, mounting bracket, and original downpipe configuration before ordering.

Professional installation is recommended.