Active Autowerke BMW B58 GESi Catted Downpipe - Fits F20 F21 F22 F23 F30 F31 F32 F33 F36 G20 G21 G22 G23 (M140i M240i 340i M340i 440i M440i) - High-Flow OBD2 Compliant 4.5in 304 Stainless

Sports Cat Front Pipe for 3.0 TwinPower Turbo Models

Transform throttle response, boost spool and exhaust tone with this premium sports catalytic converter front pipe for B58-powered 1, 2, 3 and 4 Series petrol models, including M140i, M240i, 340i, M340i, 440i and M440i. Crafted from 304 grade stainless with a large bellmouth entry, it delivers the free-flowing performance enthusiasts want while retaining emissions control and OBD II readiness.

We have installed this unit on customer cars at MJ Modifications and the feedback has been outstanding. Faster turbo response, smoother power delivery and a richer, deeper soundtrack with no drone. Customers report clean readiness monitors and no warning lights when paired with the supplied G-Sport catalyst.

Why owners choose this upgrade

• Quicker turbo spool for sharper mid-range punch and improved drivability
• Lower back pressure for more efficient power on both stock and tuned vehicles
• Refined, deeper exhaust note while keeping cabin comfort on the motorway
• Bolt-on fit, no cutting or welding, designed to mate to the factory system

Engineering that makes a difference

• Large 4.5 inch primary that tapers smoothly to 3.5 inch, then to an 80 mm outlet to maintain flow to the OEM cat-back
• Never drops below the factory 80 mm diameter for maximum performance headroom
• Precision cast stainless V-band for a perfect, leak-free seal at the turbo
• TIG-welded 304 stainless steel with a robust flex section for durability
• Manufactured in Miami, Florida to a high standard of fit and finish

G-Sport UHO catalyst details

• Ultra High Output GESi G-Sport catalytic converter that is fully OBD II compliant
• EPA certified for 1996 and newer vehicles in 49 states, engineered to reduce emissions
• Designed to prevent check engine lights, this 4.5 inch high-flow cat variant will not produce a CEL
• Rated for roughly 500 to 850 hp applications with exceptional flow capacity
• Withstands up to 1500°F and reaches operating efficiency in around 9 seconds
• 300 CPSI, furnace-brazed substrate for long-term reliability

Compatibility

• 1 Series F20 F21 LCI M140i and M140i xDrive
• 2 Series F22 F23 LCI M240i and M240i xDrive
• 3 Series F30 F31 LCI 340i and 340i xDrive
• 3 Series G20 G21 M340i and M340i xDrive
• 4 Series F32 F33 F36 LCI 440i and 440i xDrive
• 4 Series G22 G23 M440i and M440i xDrive

Important: Not suitable for OPF, GPF or PPF equipped cars.

Tech highlights

• 4.5 inch bellmouth primary
• 80 mm outlet to match the factory exhaust
• Ultra high-flow 300 CPSI catalyst

Emissions and compliance

• OBD II compliant using the GESi UHO catalyst and EPA certified in 49 states
• Not legal for vehicles registered in California

Installation

Direct replacement for the factory front catalyst on B58 petrol models. For professional fitting, contact MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Part number

11-062

Warranty

5 year or 50,000 mile warranty on the catalytic converter.

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