Wagner Tuning BMW/Toyota B58C Engine OPF-model Catless Downpipe Kit

Wagner Tuning BMW / Toyota B58C Engine OPF-Model Catless Downpipe Kit

This Wagner Tuning downpipe kit is built specifically for BMW and Toyota models running the updated B58C (also known as B58.2) engine fitted with an OPF (Otto Particulate Filter – a soot-trapping device fitted to newer petrol engines to reduce emissions). Replacing the restrictive factory downpipe with this Wagner item lowers exhaust backpressure, reduces heat soak on the turbocharger and improves exhaust gas flow. The end result is a noticeable improvement in throttle response, power and torque, along with a fuller exhaust note.

The kit is manufactured from cast stainless steel (SS304 / 1.4301), chosen for its excellent heat resistance and long-term durability. The internal shape and diameter have been CAD-engineered and flow-optimised, meaning the geometry has been calculated to move exhaust gases out of the turbo as efficiently as possible. A 3.5-inch outlet is included along with an adapter to mate up to the original exhaust system, and both lambda probe ports (the sensors that monitor exhaust gas composition) are retained for correct ECU operation.

Catless Version

This listing is for the catless version, supplied without a catalytic converter. It is intended for off-road or motorsport use where local regulations permit. If you require the version with a 200CPSI racing catalytic converter, please check the alternative SKU available on site.

Key Features

• Cast stainless steel construction (SS304 / 1.4301) for strength and heat resistance
• 3.5-inch diameter pipe with adapter to suit the original exhaust connection
• CAD-designed and flow-optimised for improved exhaust gas evacuation
• Two lambda probe connections retained for trouble-free ECU operation
• Reduces backpressure and thermal load on the turbocharger
• Direct bolt-on replacement – no cutting or fabrication required
• Replaces original BMW part number 18329897313

Why Upgrade the Downpipe?

The factory downpipe is one of the biggest restrictions in the OEM exhaust system. By opening up this section of the exhaust, the turbocharger can spool more freely and expel gases with less effort. This not only frees up additional power and torque (particularly when combined with a remap), but also helps the turbo run cooler under sustained load – which is good news for long-term reliability when the car is driven hard.

Fitment

This downpipe kit is designed for OPF-equipped BMW and Toyota models running the 3.0L B58C engine, including the BMW G20/G21 M340i, G30/G31 540i, G32 640i and Toyota A90 GR Supra (B58.2 variant). To confirm compatibility with your specific car, please use the vehicle lookup tool on this page or refer to the Vehicle Fitment tab for full details.

Important Notes

Removal of the OPF and catalytic converter will affect emissions output and is not road-legal in many regions. It is the buyer’s responsibility to ensure compliance with local laws before fitting. A supporting software calibration (remap) is strongly recommended to prevent fault codes and to make full use of the improved flow.