Stone Exhaust Mercedes-Benz A-Class W176 (M270) Valvetronic Cat-Back Exhaust System - Fits A180, A250, A250 4MATIC - Remote Valved, Plug & Play OBD, No Drone

Switchable Sports Exhaust for Mercedes A Class W176 M270 – A180, A250 and A250 4MATIC

Unlock the sound and character your MB A Class W176 should have had from factory with this switchable valve cat back from Stone Exhaust. Purpose built for the turbocharged M270 petrol engine found in A180 and A250 models, it delivers a richer tone, sharper response and tidy, bolt-on fitment for the 5 door hatchback. No guesswork, no hassle, just a premium upgrade that transforms every drive.

Big on sound, zero drone

• Active valve control with handheld remote so you choose when it’s loud or discreet
• Three modes: Open for maximum presence, Closed for refined commuting, Auto to switch by RPM
• Cruise without cabin boom on the motorway while enjoying a deep, sporty soundtrack when you want it

Plug-in control through OBD2

The supplied controller connects to the OBD2 port for a clean, plug-in install. No cutting, no splicing and no coding required. It is a genuine plug and play solution for valve operation and mode selection.

Engineered to fit like factory

• 3D scanned and reverse engineered from the OE system for precise alignment and an easy bolt-up
• 7 axis CNC bending for smooth, consistent radii and excellent flow
• Crisscross, overlapping and direct spot welding at high heat joints for strength and durability
• In house R&D and dyno development focused on flow efficiency and response

Why W176 owners choose this upgrade

• Made specifically for the M270 turbo petrol A Class – A180, A250, A250 AWD
• Remote controlled exhaust valves for instant sound control
• Refined on the inside, aggressive on the outside when valves are open
• Premium build quality and an OE style fit that looks right under the car

OPF solutions for applicable cars

Running a later vehicle with OPF sensors? A free OPF delete solution is available to prevent warning lights when using this cat back, avoiding the need for ECU coding.

Proven with our customers

We have installed this system on A180 and A250 W176 cars and customer feedback has been superb. Owners love the deeper tone with valves open, the calm cruising with valves closed and the perfect fitment. Exactly the kind of upgrade that makes every A Class feel special.

Vehicle compatibility

• Mercedes Benz A180 BlueEFFICIENCY 2012+
• Mercedes Benz A250 BlueEFFICIENCY 2012+
• Mercedes Benz A250 4MATIC BlueEFFICIENCY 2013+
• Mercedes Benz A250 Sport 2012+
• All models listed with the M270 petrol engine on the W176 chassis

Installation and fitting

Direct replacement cat back with OEM style mounting points. Professional fitting recommended for the best result.

Want us to handle the install? MJ Modifications offers expert fitting in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Manufacturer and warranty

Manufactured by Stone Exhaust

2 year warranty

Watch and listen

Sound clip – Stone Exhaust for A Class W176 M270:

Valve control and installation overview:

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