Stone Exhaust
Stone Exhaust OEM Integrated Valved Cat-Back Exhaust System for BMW X5 40i xDrive G05 & X6 40i xDrive G06 (B58)
Stone Exhaust OEM Integrated Valved Cat-Back Exhaust System for BMW X5 40i xDrive G05 & X6 40i xDrive G06 (B58)
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.
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Unlock the soundtrack your BMW deserves with a valve-controlled catback built for the B58
Give your G05 X5 40i xDrive or G06 X6 40i xDrive a deeper, richer tone and sharper response with the Stone valve-operated catback. This performance system integrates seamlessly with the factory flap control, so you get refined quiet cruising when closed and a purposeful, sporty note when open. Engineered around the B58 straight six using laser scanning, reverse engineering and in-house dyno development, it delivers the OEM-plus upgrade enthusiasts want without compromise.
At MJ Modifications we have installed this setup on customer cars and feedback has been outstanding. Crisp cold starts, a clean bass-heavy growl in sporty drive modes, and calm motorway manners with the valve shut. If you are after a premium G05 or G06 sound upgrade that looks factory, fits like factory and transforms character, this is it.
Why this catback stands out
- Factory valve integration for plug and play flap control via the original ECU and drive modes
- Dyno-developed for real-world improvements in throttle response and flow
- Harmonised acoustics for a deep tone under load with minimal cabin boom on a cruise
- Designed from precise 3D scans for a direct bolt-on install and perfect alignment
- Consistent build quality using machine welding and one-piece sections for durability
- Optional Valvetronic remote kit available with OBDII controller for manual open or close at the touch of a button
- OPF and GPF friendly when paired with the supplied module on request to avoid warning lights without coding
Engineering detail that delivers
- Laser-measured development to optimise flow, temperature and pressure characteristics
- Multi-axis CNC mandrel bending for excellent roundness and accuracy throughout the bends
- Advanced joint design and overlapping weld techniques at high-stress points for longevity
- Robotic spot welding for consistent penetration and a clean, repeatable finish
Vehicle compatibility
- BMW G05 X5 40i xDrive 2017+
- BMW G06 X6 40i xDrive 2018+
- Engine: B58
Part numbers
- AP542 - G05 X5 40i xDrive
- AP549 - G06 X6 40i xDrive
OPF and GPF equipped cars
Running a particulate filter On request we can include Stone’s OPF delete solution at no extra cost to prevent error messages when fitting to OPF or GPF vehicles. No ECU coding required.
Installation and support
Professional fitting recommended. MJ Modifications offers full installation and setup at our Warwickshire workshop. For a quote email info@mjmodifications.co.uk.
Warranty
Stone Exhaust 2 year warranty.
Looking for one of these
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