Wagner Tuning BMW B58 200 CPSI High-Flow Sports Cat Downpipe, Stainless Steel SS304 3.5-inch EU6 — Fits M140i M240i 340i 440i 540i 640i 740i X3 M40i X4 M40i — Part No. 500001027 (Non

Wagner Tuning 200‑cell Sport Catalyst for BMW B58 - AISI 304 Stainless 3.5 inch - Part No. 500001027

Give your BMW B58 straight‑six the flow it deserves with Wagner Tuning’s EU6‑rated 200‑cell metallic sport catalyst. Precision built from AISI 304 (1.4301) stainless with a full 3.5 inch primary tube and a stepped adapter to the factory system, this performance catalyst frees up exhaust flow, improves turbo response and adds a richer, more purposeful soundtrack while keeping a catted configuration. It is a direct, bolt‑on front section designed for enthusiasts who want OE‑level fit with proven gains in drivability and efficiency.

At MJ Modifications we have installed this unit on multiple B58 platforms across the UK. Feedback has been consistently positive - quicker spool, smoother mid‑range and a more engaging tone without the harshness of a decat. If you’re planning Stage 2 hardware or simply want a freer‑breathing front pipe that still uses a metal cat, this Wagner solution is the go‑to choice.

Why enthusiasts choose this catalyst upgrade

• Noticeably lower restriction vs the OE front catalyst for stronger mid‑range and top‑end
• Sharper turbo response and improved throttle feel for road and track driving
• Reduced thermal load on the turbine housing to support reliability
• Sportier, deeper exhaust character while retaining a high‑quality metal substrate
• Direct replacement fitment with adapter to the original mid‑section

Technical details

• EU6 200‑cell metallic sport catalytic converter for BMW B58 applications
• AISI 304 stainless steel (1.4301) construction for strength and corrosion resistance
• Full 3.5 inch diameter primary with stepped connection to the OEM cat‑back
• Pure bolt‑on installation - no cutting or welding required

Fitment - BMW B58 models without GPF or OPF

• F20 F21 M140i 3.0 2016 to 2018 - non GPF
• F22 F23 M240i 3.0 2016 to 2018 - non GPF
• F30 F31 F34 340i 3.0 2015 to 2018 - non GPF
• F32 F33 F36 440i 3.0 2015 to 2018 - non GPF
• G30 G31 G38 540i 3.0 2017 to 2018 - non GPF
• G32 640i 3.0 2017 to 2018 - non GPF
• G12 740i 3.0 2015 to 2018 - non GPF
• G01 X3 M40i 3.0 2017 to 2018 - non GPF
• G02 X4 M40i 3.0 2017 to 2018 - non GPF

Important: due to the increased exhaust flow from the sport catalyst, a check engine light may occur. Coding or suitable ECU calibration may be required. OPF‑equipped cars will require coding to address related fault codes. Please verify local emissions and road‑use regulations.

Installation and support

Professional fitting recommended. Replace sealing rings and hardware during installation for the best result. For expert installation, book with MJ Modifications in Warwickshire - request a quote at info@mjmodifications.co.uk.

Part number

Wagner Tuning 500001027

Warranty

2‑year manufacturer warranty.

Pre‑purchase checks

• Compatibility check available before dispatch - supply your UK registration or last 7 of the VIN at checkout
• Intended for vehicles without GPF or OPF

Search terms customers use

BMW B58 sport cat, B58 performance catalyst, 200 cell metal cat B58, BMW M140i catalyst upgrade, M240i catted front pipe, 340i catalyst replacement, 440i sport catalytic converter, 540i stainless front section, 640i GT performance cat, 740i catted down pipe alternative, X3 M40i front cat, X4 M40i sport cat, B58 exhaust upgrade, stainless 3.5 inch B58 pipe, AISI 304 1.4301 B58 catalyst, EU6 200 cell metallic substrate, BMW F series G series B58 mods, Stage 2 hardware B58, non GPF non OPF B58 catalyst, Wagner 500001027 sport cat, BMW turbo back hardware, B58 front pipe UK.