Stone Exhaust OEM-Integrated Valved Cat-Back Exhaust System for BMW 2 Series F22/F23 M240i & M240i xDrive (B58) | AP526B

Stone valve-controlled rear exhaust for BMW F22 F23 M240i and M240i xDrive B58 - Part AP526B

Give your B58-powered 2 Series the rich tone and refined manners it deserves. The Stone valve-controlled rear section and mid-pipe assembly is designed for the F22 and F23 M240i platform to elevate soundtrack, enhance flow and keep everyday comfort. It integrates with the factory valve motor for seamless drive mode operation and delivers a deeper, sportier note without the unwanted cabin boom at motorway speeds.

We have fitted Stone systems to customer cars and our own builds, and the feedback is consistently excellent. Crisp start-up bark, fuller mid‑range character and calm cruising when you want it. If you are searching for a premium M240i sound upgrade with factory-style valve functionality, precision fitment and proven development, this is the one to choose.

Key reasons enthusiasts pick this system

• Factory valve integration for true drive mode control and daily usability
• Tight-tolerance fitment developed from detailed 3D scanning and reverse engineering
• Validated on in-house dyno and acoustic rigs for flow and tone
• Confident exhaust note with minimal cabin drone when cruising
• One-piece main section with precision mechanical welds for durability
• Optional Stone Valvetronic upgrade for manual open or closed control via remote
• Plug and play OBDII controller available with the Valvetronic option
• 7 axis CNC mandrel bending for consistent diameter and smooth gas velocity

Factory-style valve control

Keep your BMW character intact. With the integrated valve setup, the car’s ECU manages the flap automatically based on drive mode and load, giving you quiet refinement on the commute and a more aggressive soundtrack when you press on.

Optional manual control

Want full say over volume. Add the Stone Valvetronic single-valve kit to switch between open and closed at the touch of a button. The plug and play OBDII module makes it easy to choose stealth or sport on demand.

Engineered for performance and longevity

Stone engineers scan the original hardware to capture pipe routing, diameters and bend angles, then simulate flow, temperature and pressure to optimise the layout. 7 axis CNC bending ensures exceptional roundness through the radius to reduce turbulence. Overlapping and crisscross weld techniques are used at high-heat joints for strength you can rely on. The result is a high quality, high precision M240i system that fits right and sounds right.

Compatibility

• BMW 2 Series F22 M240i and M240i xDrive 2015+
• BMW 2 Series F22 LCI M240i and M240i xDrive 2016+
• BMW 2 Series F23 M240i Convertible and M240i xDrive 2015+
• BMW 2 Series F23 LCI M240i Convertible and M240i xDrive 2016+
• Engine code B58

Sound and drivability

Developed using Stone’s dyno and acoustic testing, this system brings a richer, more purposeful tone while maintaining refinement for everyday use. It livens up the B58 without the harshness often associated with lesser systems.

Warranty

Stone Exhaust 2 year warranty.

Part number

AP526B

Professional fitting

Prefer expert installation. MJ Modifications in Warwickshire can supply and fit this system. Email info@mjmodifications.co.uk for a quote and availability.

Search terms customers use

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