Stone Exhaust
Stone Exhaust Valved Switchable (Valvetronic) Cat-Back for BMW 5 Series 520i G30/G31 Saloon/Touring (2016-2019) B48 – Active Valve/Flap Sport Performance Exhaust, OEM Valve Control, OPF/PPF Delete, Rear Silencer/Backbox – AP527A
Stone Exhaust Valved Switchable (Valvetronic) Cat-Back for BMW 5 Series 520i G30/G31 Saloon/Touring (2016-2019) B48 – Active Valve/Flap Sport Performance Exhaust, OEM Valve Control, OPF/PPF Delete, Rear Silencer/Backbox – AP527A
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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Switchable Catback System for BMW 5 Series G30 G31 520i B48
Part Number: AP527A - requires original bumper
Give your 5 Series the soundtrack it deserves with this premium switchable catback for the BMW G30 Saloon and G31 Touring 520i B48 2.0 turbo. Engineered to work with the factory valve, it delivers calm, refined cruising when closed and a fuller, more purposeful tone when opened. Ideal for drivers who want a tasteful performance upgrade, sharper response and everyday usability in one package.
We have installed and used this system ourselves at MJ Modifications and customer feedback has been consistently excellent. Fitment is precise, the finish is superb and the sound character is exactly what enthusiasts want from a quality BMW performance exhaust.
Why enthusiasts choose this setup
- Factory-valve compatible switchable exhaust - stealth on demand, sports tone when you want it
- Simple control via plug-and-play OBD2 valve controller
- One-piece layout for accurate fitment and smooth gas flow
- Consistent machine welding for a clean, high quality finish
- Developed using 3D scanning and reverse engineering for the B48 platform
- Designed specifically for BMW 520i G30 G31 2016 to 2019
OPF and PPF support
An OPF delete option can be supplied at no extra charge, allowing fitment to OPF or PPF equipped vehicles without triggering a warning light. Please check local laws and intended vehicle use before selecting this option.
Engineering detail
Each system is developed from OEM data captured with 3D scanning to map routing, diameter and bend geometry on the G30 G31 520i. Iteration with flow simulation focuses on maintaining velocity and managing pressure for the B48 engine.
Precision 7-axis CNC bending targets exceptional roundness through tight radii, helping reduce turbulence and improving consistency. Welding techniques include overlapping and crisscross patterns on high heat areas, with robotic spot welding used for depth and uniformity across the assembly.
Vehicle fitment
BMW 5 Series with B48 engine:
- G30 520i 2016 to 2019
- G31 520i 2016 to 2019
Great combinations
Frequently paired with the Stone B48 G20 G30 Catless Performance Downpipe 330i 520i 530i or the Stone B48 G20 G30 Eddy Catalytic Performance Downpipe 330i 520i 530i for a full B48 exhaust upgrade pathway.
Warranty
Stone Exhaust 2 year warranty.
Professional fitting
For installation, book with MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.
Search-friendly terms
BMW G30 520i sports exhaust, G31 520i Touring performance exhaust, active valve exhaust BMW 5 Series, switchable flap exhaust 2.0 turbo, BMW 520i catback UK, B48 exhaust upgrade, G30 Saloon exhaust system, G31 Touring exhaust system, BMW 5 Series valve controlled exhaust, OPF PPF compatible exhaust solution, rear silencer and centre section upgrade, performance backbox BMW 520i.
