BMW M4 (F82) Coupe 3" Secondary De-Cat Bypass Performance Exhaust

Transform the soundtrack and flow of your F82 M4

Give your S55-powered BMW M4 Coupe the race-ready edge with this 76.2 mm centre section catalyst-delete upgrade. Engineered from high quality T304 stainless steel and designed to replace the factory secondary converters in the mid-section, this track-use only solution unlocks a harder-hitting exhaust note, sharper throttle response and freer breathing for your twin-turbo straight six.

Why enthusiasts choose this centre section upgrade

• 3 inch 76.2 mm T304 stainless tubing for excellent durability and flow
• Removes the secondary catalytic converters in the middle of the system for reduced back pressure
• Compatible only with the valved rear section BM103 from Cobra Sport, retaining factory-style valve control via the cat-back
• Pre-PPF OPF cars only
• Pairs perfectly with a quality valved rear silencer to deliver a deeper, more aggressive tone under load
• Precision fitment and quality welds for a neat underbody install

Fitment and compatibility

• Chassis: BMW M4 F82 Coupe, 3.0 twin-turbo straight six S55
• Middle section replaces secondary converters only centre decat pipes
• Will fit to Cobra Sport valved cat-back BM103 only
• Pre-PPF OPF models only

Installation notes

• Requires 2 x BMW gaskets part number 18307851168 not supplied
• All other relevant fittings and hardware are included with the product
• We recommend professional installation
• For fitting, book with MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk

What you can expect

On pre-PPF F82 models, freeing up the secondary section helps the S55 breathe more easily, complements turbo spool and delivers a harder-edged, motorsport-inspired tone, especially in the higher drive modes when paired with the BM103 valved rear section. Our workshop has installed this setup for customers who wanted a louder, crisper note without changing the primary hardware, and feedback has been consistently positive on sound quality and finish.

ECU and warning light guidance

After removing the factory second converters the malfunction indicator light may come on. An ECU recalibration is recommended to maintain drivability and support any performance gains.

Usage and legal notice

This secondary catalyst removal component is sold for motorsport and off road use only worldwide. Not for road use where emissions regulations apply. Always check local laws before purchase and installation.

Search-friendly terms enthusiasts use

F82 M4 midpipe cat delete, M4 centre decat pipes, S55 catless mid section, BMW M4 track pipes, 3 inch stainless mid-pipes, M4 exhaust upgrade non-OPF, secondary cat removal kit, F82 straight pipes centre section, M4 sound upgrade, M4 race midpipe for valved cat back BM103.

Part numbers

• Compatible rear section: BM103 valved cat-back
• Required gaskets: BMW 18307851168 x 2 not included