Citroen C4 Exhaust System: Specs, Fitment & Common Faults
On the C4, a genuinely honest fact: the DPF additive never burns off, meaning even excellent driving habits can't prevent an eventual, expected filter service.
Illustration for editorial purposes
Opens live listings in a new tab.
OEM Part Number: 9839652080 (diesel DPF / SCR unit) — rear silencer (aftermarket) Bosal 135-709 / Walker 71211
| Rear silencer (back box) — aftermarket | C4 II B7: Bosal 135-709; Bosal 190-063; Bosal 190-363 (accessories needed); Walker 71211 (code 52, 800 mm); Walker 71213 (code 52, 810 mm); Walker 23228 (code 52, 960 mm). |
|---|---|
| Centre / intermediate silencer — aftermarket | C4 II B7: Bosal 135-465; Bosal 135-371; Walker 28832 (930 mm, code 52); Walker 01489 (750 mm, code 52); Vegaz CS-11 (940 mm); MTS 01.50240 |
| Front pipe / catalytic converter (DPF on diesels) — aftermarket | or DPF: Bosal 090-255 (Euro 4/5/6); Bosal 090-263 (Euro 6); Walker 28168 (code 91, 420 mm); Walker 28201 (code 92, 550 mm); Ernst 761031 (Euro 5/6, 625 mm); BM Catalysts BM91990H (Euro 5, with FK91990); JMJ 1090124 (480 mm) |
| Genuine (OE) numbers quoted | Citroen / Peugeot 9839652080 — diesel SCR / DPF unit on the 2021-on C4; none quoted for the 2010–2018 car |
| Fitment notes | no part mapped to engines. |
A Genuinely Important, Honest Fact: Good Driving Habits Alone Won't Prevent Eventual DPF Service — Citroen C4 Exhaust System
It's worth knowing something distinct from the usual "just drive faster to regenerate" advice: diesel particulate filters on this platform rely on an additive (commonly referred to as Eolys, or cerine) injected into the fuel to help the trapped soot burn at a lower temperature during regeneration. This additive itself, however, never burns off — it accumulates as a genuine ash residue inside the filter permanently, regardless of how well the car has been driven. This means even a diesel driven mostly on motorways with excellent regeneration habits will eventually need the DPF professionally cleaned or replaced simply due to this ash buildup, typically somewhere in the region of 100,000-120,000 miles — this isn't a fault or a sign of poor maintenance, but a genuine, expected part of diesel particulate filter technology.
If you're chasing a specific EGR-related fault, real fault codes worth knowing include P0401 (insufficient EGR flow) and P0405 (EGR position sensor signal fault) — worth mentioning to whoever is diagnosing the car, since these point toward different specific parts of the system.
Citroen C4 Exhaust System: The Part That Announces Its Own Problems
On the Citroen C4, sound is usually the first clue here, ahead of any visual sign — a rattle, a drone, noise that's crept in gradually or arrived overnight. It's one of the more forgiving faults in that sense, since your ears will likely flag it before it becomes a bigger problem.
Citroen C4 Exhaust System: Watch: Replacing It
Weak: generation not confirmed from title (could be 2004-2010).
Citroen C4 Exhaust System: What It Does
The Citroen C4's exhaust system handles three things at once: clearing burnt gases from the engine, cutting noise via the silencer, and treating emissions through a catalytic converter and particulate filter. Because petrol and diesel emissions requirements differ, it often uses genuinely different exhaust systems depending on engine type.
Opens live listings in a new tab.
Citroen C4 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 Citroen Exhaust System
The same part, covered across other Citroen models.