Mercedes W177, A45/A45S AMG Stainless Steel Valved Catback Exhaust

Give the M139 in your Mercedes-AMG A45 S the voice it always deserved with this Stainless Steel Valved Catback Exhaust — a full replacement of the centre and rear sections, built around a twin-valved rear muffler and twin tips, and supplied with the valve remote kit.

The A45 S makes more power per litre than almost anything else on the road, and then the factory exhaust spends all of it keeping quiet. European drive-by noise limits are the reason the standard system is as silenced as it is, and they are why a car this quick can sound so ordinary from outside. This system replaces the standard centre and rear sections with mandrel-bent 304 stainless tubing and a valved rear muffler.

The valves are operated from the supplied remote, so the volume is your decision rather than something the throttle position decides for you. Closed, it is close enough to standard for an early morning. Open, it is a different car entirely.

Key Features

Independent Varex Valve System

Rather than reusing the restricted factory valves, this system operates its own dedicated valve assembly with complete travel in both directions. Sealed when closed for quiet running, and fully unobstructed when open for maximum flow and volume.

304 Stainless Steel Construction

Mandrel-bent 304 stainless throughout for a consistent bore through every corner, corrosion resistance and a long service life under Australian conditions.

Twin Valve Rear Muffler

A valve on each exit rather than a single restriction, so both sides of the system open together and the note stays even across the car.

Remote Kit Supplied

The handset, receiver and loom are included in the box. Nothing else to buy and no connection to the factory valve motors.

Precision TIG Welded

Clean, strong welds built to survive the heat cycling and vibration a hard-driven turbo four puts through an exhaust.

Direct Bolt-On Fitment

Fits at the factory mounting points and hangers, using the original rubber isolators. No cutting and no fabrication.

Performance Benefits

A deeper, far louder exhaust note with the valves open
Near-standard volume with the valves closed
Reduced restriction through the centre and rear sections
Sharper throttle response and a more urgent top end
Lighter than the heavily silenced factory system
A proper foundation for a tuned A45 S

W177 Hatch Only - Check Before You Order

This is a full rear-section replacement, and a rear section follows the body rather than the engine. It is shaped for the W177 A45 hatch and nothing else.

Our M139 downpipes cover the A45, the CLA45 and the GLA45, because those follow the engine and all three share it. This catback does not. A C118 CLA45 is a four-door coupe and an H247 GLA45 is an SUV — different floor, different silencer position, different exit geometry. If you have either of those, contact us rather than ordering this.

Vehicle Fitment

Mercedes-AMG A45 / A45 S - W177 (2019-2025)

2.0L Turbocharged M139 Engine

Hatch body only

Please Note

Professional installation is recommended. Exhaust sound will vary depending on whether a factory or aftermarket downpipe is fitted.

Check your local road rules before fitting. Exhaust noise requirements vary by state and a vehicle must remain compliant for road use.

Why Choose Proven Performance Parts

We specialise in high-performance parts for European vehicles — Volkswagen GTI & R models, Audi S/RS platforms, BMW M cars and Mercedes-AMG. Every product we offer is carefully selected for its quality, fitment, and real-world performance — tested by enthusiasts, for enthusiasts.