Wagner Tuning B58 Catted Downpipe Kit for M140i M240i 340i 440i

The Wagner Tuning B58 Catted Downpipe is a high-flow, motorsport-grade upgrade designed to replace the restrictive OEM catalytic converter on BMW F-Series B58 models. Built to improve exhaust flow, turbo response and overall performance, this downpipe features a high-quality sport catalyst engineered for fast-road use, tuned applications and track environments where a catted system is preferred.

With precision stainless-steel construction and OEM-style fitment, Wagner’s catted downpipe provides a proven, reliable solution for B58 drivers looking to unlock power gains without excessive noise or compromise in drivability.

Key Features

• High-flow sports catalyst for increased exhaust velocity

• TIG-welded stainless-steel construction for durability

• Reduces turbo lag and improves throttle response

• Designed to support Stage 1 and Stage 2 power levels

• OEM-style mounting points for direct bolt-on installation

• Improved mid-range torque and enhanced overall performance

• Designed for B58 Gen 1 F-Series models

• Suitable for fast-road and track use

Compatibility

BMW F-Series B58 Models

• M140i (F20/F21)

• M240i (F22/F23)

• 340i (F30/F31/F34)

• 440i (F32/F33/F36)

• X3 M40i / X4 M40i (selected F-series variants with B58 Gen 1)

(Fits most Gen 1 B58 F-Series models. Not suitable for G-Series or OPF-equipped cars.)

Ideal For

• Tuned B58 engines running Stage 1 or Stage 2 software

• Fast-road and track users wanting better turbo efficiency

• Cars fitted with upgraded intercoolers, intakes or turbo systems

• Drivers who want the performance benefits of a downpipe without going fully decat

• Owners looking to reduce heat and backpressure while maintaining refined sound levels

Why Choose the Wagner Tuning B58 Catted Downpipe Kit

Wagner Tuning is renowned for delivering high-quality, high-flow exhaust components suitable for both road and motorsport use. Their B58 catted downpipe significantly improves exhaust gas flow compared to the OEM unit, unlocking power and reducing turbo strain — especially beneficial for tuned vehicles.

The use of a high-flow sport catalyst retains a cleaner emission profile and a more controlled exhaust tone while offering the durability and precision fitment that Wagner products are known for. For B58 owners wanting reliable, consistent and measurable performance gains, this downpipe is one of the most trusted options on the market.

Installing / Notes

• Professional installation recommended due to fitment tolerances and sensor handling

• Software calibration advised to optimise performance and avoid CEL warnings

• Designed for off-road, track or motorsport use where regulations permit

• Not suitable for OPF/GPF-equipped vehicles