Mercedes-Benz A-Class Exhaust System: Specs, Fitment & Common Faults
A genuinely useful, money-saving finding: a "DPF not working efficiently" fault is most commonly caused by a failed, comparatively cheap pressure sensor rather than the expensive DPF itself — plus a finding that regeneration won't happen below around 15 litres of fuel.
Illustration for editorial purposes
Opens live listings in a new tab.
OEM Part Number: confirm via VIN — Rear silencer (aftermarket) Walker 23091
| Rear silencer (back box) — aftermarket | Walker 23091 (860 mm, code 52); Walker 24332 (1080 mm, code 63); Vegaz MS-22 / MS-2 / MS-6IMA / MS-13IMA / MS-332; Polmo 13.11; Hella 8LD 366 033-101 / -141 / -251 / -301, 034-901 (sets) |
|---|---|
| Centre / intermediate silencer — aftermarket | Bosal 175-003 / 175-123 / 175-185 / 175-429 / 176-421 (accessories needed); Ernst 350143 (770 mm), 350051 (800 mm); Vegaz MS-420, MS-421, MS-489 (rear, 1090 mm), MS-175IMA, MS-117; Izawit 07.009; Polmo 13.07; MTS 01.53450 |
| Front pipe / catalytic converter (DPF on diesels) — aftermarket | NAP CAK11584 (Euro 6, 460 mm), CAK11533 (Euro 6, 350 mm); Vegaz MK-400 (Euro 6), MK-319 (Euro 4); Walker 28962 / 20952 / 28196; Quinton Hazell QCAT80227H / 80180H; NAP CAK10455 (OM646/OM611 diesel codes); JMJ 1080252 (OM646); Ernst 465175 (front repair pipe) |
| Genuine (OE) numbers quoted | None quoted in catalogue listings — order genuine parts against your VIN |
| Fitment notes | petrol A160-A45 AMG, diesel A160 CDI-A220d; not engine-specific |
Mercedes-Benz A-Class Exhaust System: The Part That Announces Its Own Problems
On the Mercedes-Benz A-Class, most faults are things you'd spot visually first, but this one usually announces itself acoustically — a rattle, a drone, a noticeable jump in noise levels. That's actually helpful, since it means you'll likely notice trouble well before it gets serious.
Mercedes-Benz A-Class Exhaust System: What It Does
Three jobs happen inside the Mercedes-Benz A-Class's exhaust system: routing burnt gases away from the engine, quieting them through the silencer, and treating emissions via a catalytic converter and particulate filter. Petrol and diesel variants often need completely different systems to meet their respective emissions requirements.
Mercedes-Benz A-Class Exhaust System: Watch: Replacing It
Aftermarket full exhaust fit on W176
Opens live listings in a new tab.
A Genuinely Useful, Money-Saving Finding Worth Knowing — Mercedes-Benz A-Class Exhaust System
If a "DPF not working efficiently" fault code has appeared, this is genuinely worth knowing on related diesel engines: this specific code is most commonly caused by a failed DPF differential pressure sensor, or a blockage in the pipes connecting it, rather than a genuine fault with the expensive DPF itself. A replacement sensor is comparatively cheap and considered a straightforward DIY-friendly job, worth checking this specific sensor before assuming a full DPF replacement is necessary.
It's also genuinely worth knowing that a dealer can check the DPF's fill level using their diagnostic equipment, and if it's found to be around 80% or higher, a good long run at higher revs on the motorway is typically the recommended first step before booking the car in for further investigation.
Mercedes-Benz A-Class Exhaust System: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Exhaust System Guide for warning signs and fault codes to watch for, confirming fitment against your VIN, and which aftermarket brands are worth trusting.
More Mercedes-Benz Exhaust System
The same part, covered across other Mercedes-Benz models.