Valved Exhaust System for Mercedes-AMG A45 / A45 S W177 2.0 turbo (2020-2022)
Configuration
Mercedes-AMG A45 / A45 S W177 Valved Exhaust System (2020-2022)
Valves
Operated by remote control, factory-paired.
Estimated at 0.50 m from the outlet, 45°, 2,000 rpm with a warm engine. Allow ± 2 dB depending on the engine and measuring point. A 3 dB difference is audible in a direct comparison; 10 dB sounds roughly twice as loud.
Configuration guide
Sound intensity with the valves open, on a scale of 0 to 10.
| Configuration | Intensity |
|---|---|
| Decat downpipe + Rog cat-back | 10/10 |
| 100-cell sports catalytic converter + Rog cat-back | 9/10 |
| 200-cell sports catalytic converter + Rog cat-back | 8/10 |
| Rog cat-back only, factory catalytic converter retained | 7/10 |
| Factory exhaust, for comparison | 3/10 |
The Mercedes-AMG A45 W177 exhaust in detail.
Two versions share this system: the A45 (387 hp, 480 Nm) and the A45 S (421 hp, 500 Nm), both on the W177 hatchback from 2020 to 2022. Their engine, the M139, is officially the most powerful series-production turbocharged four-cylinder in the world, hand-built on the “One Man, One Engine” principle. Its peculiarity: the block is rotated by 180°, with the manifold and turbo on the bulkhead side and the intake at the front.
Particulate filter included, the factory exhaust makes this racing engine sound like an ordinary hatchback. The valved Rog cat-back gives it back a fierce, full tone, an aggressive climb to the red line and rich crackles, with the valves open. With the valves closed, the AMG becomes civilised again, as close as possible to its original voice: it does not change its nature, it changes its volume when you decide.
Built to your VIN, the system fits with band clamps and gaskets, no welding or cutting, in about two hours on a lift. If your A45 has its factory valves, the AMG drive modes keep controlling them; otherwise a box in the boot and the Rog remote do the job, with two buttons.
On the M139, the main restriction is the downpipe that carries the catalytic converter; this page offers it under the “Manifold” option. The 200-cell keeps emissions control, the 100-cell and the decat version do not. Fitted alone, this part brings sound and a little weight saving; it is with an ECU remap that it releases power. You then choose 304 stainless steel, durable with a round sound, or titanium, around 40% lighter and finished in brushed, gold or purple.
Mercedes-AMG A45 / A45 S W177 2.0 turbo exhaust specifications.
| System type | Valved cat-back (valve exhaust), built to your VIN |
|---|---|
| Vehicles and chassis code | Mercedes-AMG A45 and A45 S, W177 hatchback |
| Engine | M139, 2.0-litre turbocharged four-cylinder, 387 hp / 480 Nm (A45) or 421 hp / 500 Nm (A45 S) |
| Years | 2020-2022 |
| Materials and finishes | 304 stainless steel or titanium; titanium in brushed, gold or purple |
| Valves | Factory AMG drive modes or the Rog remote |
| Front section (option) | Downpipe with 200-cell or 100-cell catalytic converter, or decat |
| Fitting | Clamps and gaskets, no welding, about 2 hours |
| Manufacturing and delivery | Made to order, 20 working days, free delivery |
| Warranty | 3 years, parts and workmanship |
Questions about the Mercedes-AMG A45 / A45 S W177 2.0 turbo exhaust.
Is the system the same for the A45 and the A45 S?
Yes: 387 or 421 hp, both W177 versions from 2020 to 2022 take the same Rog system. Your VIN lets us check compatibility before we start manufacturing. The CLA45 S C118 and the earlier A45 W176 have their own pages.
Does the A45 S need an ECU remap?
Not for the cat-back, which leaves the original electronics untouched. The system alone brings a moderate gain through lower back pressure; the real potential of the M139 opens up at Stage 2, with a downpipe and an ECU remap at an approved tuner: the published figures for the 421 hp version reach 490 hp and 600 Nm.
Mercedes-AMG A45 / A45 S W177 2.0 turbo with a Rog exhaust: what should you know about vehicle inspection?
Present it with the valves closed: the sound stays close to stock. With the cat-back alone or the 200-cell sport catalytic converter, emissions control is kept. With the 100-cell, everything depends on the car and local rules; the decat version is aimed at the track.
What does the “Manifold” option change on the M139?
Despite its name, on this turbocharged engine it replaces the downpipe and its catalytic converter, the main restriction on the M139. On an A45 without an ECU remap, the benefit is limited to sound and a little weight saving. The 200-cell remains the road choice; the 100-cell and the decat version are meant for more extreme use.
How long does it take to equip the A45?
Your system is made for your car: 20 working days between order confirmation and delivery, shipping free of charge. Fitting then takes around two hours at the garage of your choice.
Mercedes-AMG A45 / A45 S W177 2.0 turbo: Does a valved exhaust system drone?
No. With the valves closed, the gases flow through the whole rear silencer and the cabin stays calm at a steady speed. Our Rog exhausts are designed to avoid drone. Learn more: Why our systems stay calm on the motorway.
Mercedes-AMG A45 / A45 S W177 2.0 turbo: straight pipe or resonator?
On this model, two characters at the same price: the straight pipe for the raw sound of your engine, unfiltered, or the resonator for a rounder and slightly softer voice. Either way, the exhaust stays fully sporty. Learn more: Exhaust resonator: what does it do? Straight pipe or resonator, which sound to choose.
Rog expert guide
Mercedes A45 S AMG W177: the M139 unmuzzled, the complete exhaust system guide
421 hp from a series-production four-cylinder: the M139 in the A45 S still holds the title, and it is hand-built like an AMG V8. Its factory exhaust, however, lets almost none of this achievement through. Here, point by point, is...
In detail
Rog Advisor
A question about this exhaust?
Fitment, sound, catalyst, valves, delivery: the answer comes straight away, with your configuration in context.
The Rog Advisor is an automated assistant trained on our product pages and answers. For an important decision, write to us: we confirm by e-mail.
Unsure about your configuration? Talk to us before you order. We know your car. Write to us at contact@rogmotorsport.com: we reply in writing, in English, within 24 hours. Email us
Reviews imported from our previous system and translated from French; verified purchases carry the badge.
Rog presentation film: choosing your vehicle, Standard or Equal Length design, stainless steel or titanium, Z-Pipe, controlled valves, titanium and tip finishes, and support from choosing your configuration through to shipping.
THE Rog CRAFT
Our process.
From the first bend to the last check. The same care at every step.
-
Design
Designed for your vehicle.
Geometry matched to your model, carefully studied bends and precise mounting points. Everything starts with accurate design.
-
Manufacture
Crafted with precision.
Tube bending, part fitting and TIG welding: every joint receives the same care.
-
Finishing
Material, elevated.
The finish reveals the character of the metal. Stainless steel or titanium, depending on the options available for your vehicle.
-
Assembly
Every part in its place.
Components are assembled and adjusted. On valved systems, the mechanism is fitted, set up and tested.
-
Inspection
Check. Then approve.
Geometry, welds, connections and gas flow: the key points are inspected before shipping.
-
Shipping
Ready to join you.
Reinforced packaging protects your exhaust in transit. The final step before giving your vehicle a new voice.
Customer builds
Your videos & photos
The Rog lines fitted on our customers' vehicles, in real conditions.
- Builds
- 500+
- Brands
- 28
- Satisfaction
- 4,9
The journal
News & advice
Best valved exhaust for the Mercedes-AMG A45 / A45 S W177
Which valved exhaust for a Mercedes-AMG A45 or A45 S W177? The options compared (sound, material, valves) and the Rog...
Read the articleBest valved exhaust for the Audi RS3 8Y
Which valved exhaust for an Audi RS3 8Y? The options compared (sound, material, valves) and the Rog system made to...
Read the articleBest valved exhaust for the BMW M2 G87
Which valved exhaust for a BMW M2 G87? The options compared (sound, material, valves) and the Rog system made to...
Read the articleExhaust rules: what changes in 2026 and 2027 (Euro 7, noise cameras, MOT)
Euro 7, new-car noise, noise cameras, MOT and vehicle inspection, and models: what really changes in 2026 and 2027 for...
Read the articleChanging your exhaust: what inspections and approvals cost in 9 countries
What the periodic inspection and the check of a modification cost after changing your exhaust, in 9 European countries: official...
Read the articleIs a cat-back exhaust legal in Ireland? What the NCT checks.
A cat-back leaves your factory cat, sensors and OBD as they are; valves closed, very close to stock, valves open,...
Read the articleSports exhaust (sportsummuti) in Estonia: what the tehnoülevaatus checks.
The sound you choose, a discreet car when it matters: what a Rog valved exhaust gives you in Estonia, how...
Read the articleSports exhaust in Latvia: tehniskā apskate and the CSDD noise limit.
The sound you choose, a discreet car when it matters: what a Rog valved exhaust gives you in Latvia, how...
Read the articleNo article matches this search.
All articles