Wagner Tuning B58 Catless Downpipe Kit for BMW Fxx M140i M240i 340i 440i

The Wagner Tuning B58 Catless Downpipe is a high-flow, competition-focused exhaust upgrade engineered for BMW F-Series models equipped with the first-generation B58 engine. By removing the factory catalytic converter, this downpipe offers the least restrictive exhaust path possible — improving turbo spool, reducing backpressure and maximising performance potential for high-power builds.

Designed for track, off-road and motorsport use, the Wagner catless downpipe is perfect for drivers who want uncompromised flow, stronger mid-range torque and faster turbo response from their B58-powered BMW.

Key Features

• Completely catless design for maximum exhaust flow

• Significant reduction in backpressure and turbo spool time

• TIG-welded stainless-steel construction for long-term durability

• Supports Stage 2 and high-output B58 builds

• OEM-style mounting points for straightforward fitment

• Improved throttle response and stronger mid-range pull

• Designed specifically for B58 Gen 1 F-Series applications

• Ideal for track and competition environments

Compatibility

BMW F-Series B58 Models (Gen 1)

• M140i (F20/F21)

• M240i (F22/F23)

• 340i (F30/F31/F34)

• 440i (F32/F33/F36)

• X3 M40i / X4 M40i (selected B58 F-Series models)

(Not suitable for G-Series, OPF/GPF-equipped or B58TU vehicles.)

Ideal For

• High-power B58 builds requiring maximum exhaust flow

• Track-driven cars where catalytic restrictions limit performance

• Vehicles fitted with hybrid turbos or upgraded fuelling

• Drivers wanting sharper, faster turbo spool and stronger torque delivery

• Owners looking for a motorsport-grade exhaust upgrade to pair with Stage 2 software

Why Choose the Wagner Tuning B58 Catless Downpipe Kit

For drivers chasing maximum performance from the B58 engine, a catless downpipe is one of the most impactful hardware upgrades. Wagner’s catless system is built using premium stainless steel with precise TIG welds, ensuring excellent strength and durability even under extreme heat and boost pressure.

By eliminating the catalytic converter, exhaust flow improves dramatically — reducing turbo strain, lowering EGTs and unlocking noticeably quicker spool. Wagner’s reputation for precise fitment and robust engineering makes this one of the most trusted catless downpipes for the F-Series B58 platform.

Installing / Notes

• For off-road, competition or motorsport use only

• Professional installation recommended

• ECU tuning is required to avoid check-engine lights and optimise performance

• Not suitable for road use in many regions

• Not compatible with OPF/GPF-equipped cars