Stone Exhaust Valvetronic Cat-Back for Mercedes A-Class W176 A180/A250/A250 4MATIC (M270) 2016–2018 Facelift – Remote/OBDII Valved – Pre Bumper – MP508S

Switchable Catback System for Mercedes A-Class W176 A180 A250 A250 4MATIC 2016 to 2018 Facelift — Part No. MP508S

Transform your M270-powered A-Class with a premium switchable rear section that delivers serious soundtrack and everyday refinement. This electronically controlled valve system gives you quiet commuting and instant sport mode at the press of a button, all while maintaining OEM-level fit and finish. Developed with 3D scanning, dyno refinement and precision bending, it is the upgrade discerning A-Class drivers choose when searching for a performance exhaust that actually fits, sounds right and enhances response.

Why enthusiasts choose this upgrade

• Valve-controlled catback for W176 A-Class A180, A250 and A250 4MATIC facelift models
• Remote key fob and OBDII plug-in controller with ON, OFF and AUTO modes for instant sound management
• One-piece performance layout engineered for optimal flow and fewer potential leak points
• Dyno-developed for sharper throttle feel and real-world drivability
• Tuned to keep drone at bay for relaxed motorway cruising
• 7-axis CNC-bent pipework preserves roundness and accuracy for consistent gas speed
• Precision reverse-engineered from OEM components for factory-style alignment
• Advanced welding techniques applied at high-stress joints for long-term durability
• Pre-bumper configuration to suit the relevant facelift models listed below

Switchable valves. Calm when closed. Character when open.

Use the supplied remote to toggle sound profiles. Keep it subtle for early starts and neighbourhood friendliness, then open the valves for a deeper, more engaging tone when the road opens up. Select AUTO to link valve behaviour to a set RPM so it adapts to your driving without constant switching.

Engineered for accuracy and flow

Every mounting point and bend is captured via 3D scanning, then modelled for flow and temperature management before production. The result is a catback that bolts up cleanly, sits correctly and performs consistently.

Weld quality you can trust

Crisscross and overlapping welds increase penetration and strength, while direct spot welding provides consistent accuracy across key joints. Built to handle hard road use without fuss.

OPF solution available

Running an OPF/GPF car? An OPF delete option is available at no additional charge to prevent error codes, so there is no ECU coding required for fitment.

Compatibility

Engine: M270

Chassis: Mercedes-Benz A-Class W176 5-door hatchback, Facelift 2016 to 2018

• A180 BlueEFFICIENCY 2016 to 2018
• A250 BlueEFFICIENCY 2016 to 2018
• A250 4MATIC BlueEFFICIENCY 2016 to 2018
• A250 Sport 2016 to 2018

Pre-bumper configuration as listed.

Part number

MP508S

Installation

We recommend professional fitting. MJ Modifications offers expert installation at our Warwickshire workshop. For a quote and booking, email info@mjmodifications.co.uk.

Tried, fitted and loved by our customers

We have installed this system for many W176 owners. Feedback is consistently positive: a tasteful everyday tone with valves shut, a rich, sporty soundtrack with valves open and a noticeable improvement in responsiveness. It looks right, fits right and sounds superb.

Warranty

Manufacturer warranty: 2 years.

Videos

Valved system installation

Sound clip — A-Class W176 A250

Helpful search terms

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