BMW B58 5" Super Sport Cat Downpipe 200 Cell High-Flow Sports Catalyst, 5in to 4in Flexi MOT-Friendly, No EML Osprey Performance Fits M140i M240i 340i 440i 540i 740i X3/X4 M40i (B58)

Osprey Performance Catted Downpipe for BMW B58

Give your B58-powered BMW the breathing room it deserves with Osprey Performance’s large-bore catted downpipe. Featuring an oversized 5 inch primary that gently transitions into a 4 inch flex section, this high-flow 200 CPSI metallic core converter is engineered to minimise restriction, sharpen turbo spool and deliver real gains you can feel on the road. Designed to be test-friendly in the UK and to avoid triggering dashboard warnings, it is the sweet spot for daily-driven performance without the compromises of a straight-through pipe.

This is Osprey’s largest diameter B58 catted pipework to date and is widely regarded for flow that rivals a decat, so you get the punch, response and top-end pull enthusiasts want while retaining a catalyst for emissions control. If you are hunting for a B58 catted downpipe upgrade that balances performance and practicality, this is the one to fit.

Why it stands out

• Oversized 5 inch inlet tapering to a 4 inch flex section for exceptional exhaust gas velocity and rapid spool
• 200 CPSI high-flow catalyst designed to be UK test friendly and to keep the dash free from warning lights
• Flow characteristics comparable to a decat for strong mid-range torque and improved top-end power
• Smooth step-down design to reduce backpressure and maintain velocity through the system
• Direct-fit solution for B58 models listed below for a hassle-free performance upgrade

Real-world results you can trust

We run this part on our own B58 builds and customer cars at MJ Modifications. Feedback has been consistently excellent, with owners praising faster spool, stronger pull through the revs and a more engaging drive. It is a favourite for stage 1 and stage 2 style setups where reliability and drivability matter.

Compatible vehicles

BMW B58 petrol models including M140i, M240i, 340i, 440i, 540i, 740i, X3 M40i and X4 M40i.

Ideal search terms

BMW B58 catted downpipe upgrade, B58 200 CPSI converter, BMW M140i catted pipe, M240i high-flow cat, 340i catted exhaust, 440i down pipe upgrade, 540i performance catalyst, 740i B58 exhaust mod, X3 M40i catted down pipe, X4 M40i B58 cat upgrade, large-bore B58 downpipe, B58 turbo spool improvement, reduced backpressure B58, B58 exhaust flow upgrade.

Fitting and support

Professional installation recommended. For fitting, book with MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Brand: Osprey Performance