BMW B58 Gen 1 F-Series M340i/M440i/M240i Catless/Catted Downpipe

BMW B58 Gen 1 F-Series M140i/M240i/340i/440i Catless/Catted Downpipe

Unlock the full performance potential of your BMW B58-powered F-Series platform with this Catless or High-Flow Catted Downpipe — engineered to maximise exhaust flow, improve turbocharger efficiency, and unleash the true performance and sound of BMW's renowned turbocharged inline-six.

Designed specifically for the B58 Gen 1 engine, this high-flow downpipe replaces the restrictive factory catalytic converter, significantly reducing exhaust backpressure and allowing the turbocharger to spool faster and operate more efficiently. Available in both Catless and High-Flow Catted configurations, this upgrade delivers sharper throttle response, increased power potential, enhanced turbo acoustics, and a noticeably more aggressive exhaust note.

Constructed from premium T304 stainless steel with precision TIG welding and mandrel-bent tubing, this downpipe is built to withstand extreme exhaust temperatures while providing outstanding durability and corrosion resistance. Its direct bolt-on design ensures straightforward installation using the factory mounting locations.

Whether paired with the factory exhaust system or a complete aftermarket setup, this Catless/Catted Downpipe is one of the most effective performance upgrades available for the BMW B58 Gen 1 platform.

Key Features

Catless or High-Flow Catted Configurations

Available in either Catless form for maximum exhaust flow and performance, or with a high-flow catalytic converter for a more refined exhaust note and improved emissions compliance.

Premium T304 Stainless Steel Construction

Manufactured from corrosion-resistant T304 stainless steel for exceptional durability and heat resistance.

Increased Exhaust Flow

Reduces exhaust backpressure, allowing the turbocharger to spool faster and operate more efficiently.

Mandrel-Bent Tubing

Maintains unrestricted exhaust flow and consistent pipe diameter throughout the system.

Precision TIG Welded

Engineered for superior strength and long-term reliability in demanding performance applications.

Direct Bolt-On Fitment

Designed specifically for BMW B58 Gen 1 F-Series vehicles using factory mounting locations.

Performance Benefits

• Increased horsepower and torque potential
• Faster turbo spool
• Improved throttle response
• Reduced exhaust backpressure
• Enhanced turbocharger efficiency
• Increased turbo whistle and induction acoustics
• Ideal foundation for Stage 1, Stage 2, and higher-performance builds

Performance gains may vary depending on ECU calibration, fuel quality, and supporting modifications.

Sound Characteristics

Catless Version

• Deeper and more aggressive exhaust tone
• Increased turbo spool and whistle acoustics
• Louder cold starts
• Enhanced pops and burbles (when tuned)
• Maximum exhaust flow and performance

High-Flow Catted Version

• Sportier and more refined exhaust note
• Increased turbo spool acoustics
• Improved exhaust volume without excessive harshness
• Excellent balance between performance and everyday drivability

Vehicle Fitment

BMW F20/F21 M140i (2016–2019)
BMW F22/F23 M240i (2016–2021)
BMW F30/F31/F34 340i (2016–2019)
BMW F32/F33/F36 440i (2016–2020)

3.0L Turbocharged B58 Gen 1 Engine

Please Note

Professional installation is strongly recommended.

Performance gains will vary depending on vehicle condition, fuel quality, ECU calibration, and supporting modifications.

The Catless version is intended for off-road and motorsport use only.

ECU tuning is recommended to maximise performance and prevent potential check engine lights associated with catalyst removal.

Why Choose Proven Performance Parts

We specialise in high-performance parts for European vehicles — including Volkswagen GTI & R models, Audi S/RS platforms, and BMW M vehicles. Every product we offer is carefully selected for its quality, fitment, and real-world performance — tested by enthusiasts, for enthusiasts.