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Stone Exhaust

Stone Exhaust BMW B58 Performance Catless/Decat Downpipe | F20 F21 F22 F23 F30 F31 F32 F33 F36 G11 G12 G30 G31 G02 G05 G06 G29 | M140i M240i 340i 440i 540i 740i X3/X4 M40i X5/X6 40i Z4 M40i | A214P

Stone Exhaust BMW B58 Performance Catless/Decat Downpipe | F20 F21 F22 F23 F30 F31 F32 F33 F36 G11 G12 G30 G31 G02 G05 G06 G29 | M140i M240i 340i 440i 540i 740i X3/X4 M40i X5/X6 40i Z4 M40i | A214P

£960.96
£1,201.20 £960.96
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Heads-up on cancellations & returns: if you cancel an order or return an item, you won't get back 100% of what you paid. We apply a 10% restocking fee, the outbound shipping is non-refundable, and we have to pass on Shopify / PayPal payment processing fees; these aren't returned to us when we refund you. International orders also lose on exchange-rate spread in both directions. If the original packaging is damaged or missing, a reboxing charge applies. For international orders specifically, if you refuse to pay our shipping invoice or supply a prepaid label after placing the order, the same deductions apply. We're upfront about this — please be sure of your purchase before ordering.

Stone Exhaust B58 Race Decat Front Pipe for BMW | Part A214P

Looking for a serious exhaust upgrade for your B58-powered BMW without compromise on fitment or durability? This Stone Exhaust cat delete front section is built to free up turbo flow, sharpen response and unlock a harder, more purposeful soundtrack. Designed around the factory layout for exact alignment, it replaces the restrictive primary catalyst with a smooth, one-piece, high-flow solution developed using 3D scanning, reverse engineering and precision robot welding.

Compatible across a wide range of 3.0 turbo BMW models and chassis codes including F20 F21 F22 F23 F30 F31 F32 F33 F36 G11 G12 G30 G31 G02 G05 G06 G29, plus M140i, M240i, 340i, 440i, 540i, 740i, X3 M40i, X4 M40i, X5 40i, X6 40i and Z4 M40i.

Why enthusiasts choose this B58 decat pipe

  • Cat delete design to maximise exhaust gas velocity and reduce back pressure
  • One-piece CNC bent tubing for a seamless, uninterrupted internal bore
  • Dedicated flex section helps manage thermal expansion and vibration
  • Crisscross, overlapping turbo flange welds strengthen the hottest joint
  • Robot-assisted machine welding for consistent penetration and accuracy
  • Engineered from 3D scans of OE parts to ensure 100 percent factory-style fit
  • Built to outperform typical multi-piece or segmented alternatives

Engineering that delivers

Stone Exhaust validates flow with velocity measurement and 3D simulation, refining routing and transitions until pressure rise is minimised. A 7-axis CNC bending process maintains roundness at tight radii to avoid the ovalisation and internal steps that can disturb gas flow. Mechanical welding arms and direct spot welding create an integrally formed assembly with outstanding repeatability.

Stone Exhaust B58 decat engineering and 3D scanning - MJ Modifications UK
7-axis CNC bending for BMW B58 race pipe - MJ Modifications UK
Precision robot welding on B58 turbo flange - MJ Modifications UK

Proven by us

We have fitted these Stone Exhaust B58 decat pipes on customer cars and our own shop vehicles at MJ Modifications, and feedback has been consistently excellent. Fitment is spot on, the finish is superb and the performance feel is immediate with crisper spool and a deeper, more engaging tone.

Vehicle compatibility

BMW 1 Series

  • F20 LCI / F21 LCI M140i / M140i xDrive

BMW 2 Series

  • F22 M240i / M240i xDrive
  • F22 LCI M240i / M240i xDrive
  • F23 M240i / M240i xDrive
  • F23 LCI M240i / M240i xDrive

BMW 3 Series

  • F30 LCI / F31 LCI 340i / 340i xDrive

BMW 4 Series

  • F32 440i / 440i xDrive
  • F32 LCI 440i / 440i xDrive
  • F33 440i / 440i xDrive
  • F33 LCI 440i / 440i xDrive
  • F36 440i / 440i xDrive
  • F36 LCI 440i / 440i xDrive

BMW 5 Series

  • G30 540i / 540i xDrive
  • G31 540i xDrive

BMW 7 Series

  • G11 740i
  • G12 740i / 740i xDrive
  • G12 740Li / 740Li xDrive

BMW X models

  • G02 X4 M40i / X3 M40i xDrive
  • G05 X5 40i xDrive
  • G06 X6 40i xDrive

BMW Z series

  • G29 Z4 M40i

Part number

A214P

Manufacturer

Stone Exhaust

Warranty

Stone Exhaust 2-year warranty

Fitting and support

Professional installation, coding advice and post-fit checks available at MJ Modifications in Warwickshire. For a fitting quote or to discuss your B58 exhaust upgrade, email info@mjmodifications.co.uk.

Tuning calibration is recommended to maximise performance from this hardware.

Important notice

This is a catless race component intended for off-road and track use only. Check local regulations before purchase.

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