Ford Focus Mk3 Exhaust System: Specs, Fitment & Common Faults
A confirmed, major current recall covers DPF cracking on 2.0-litre diesel Focus models built 2018-2023 — check your registration before anything else.
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A Genuinely Major, Current Recall Worth Checking If You Have a Diesel
This is worth checking directly against your registration if you own a diesel Focus: Ford has confirmed a major recall (reference 24E06, with a specific Focus-targeted update under reference 15307R covering 35,146 UK 2.0-litre diesel Focus models built between 23 April 2018 and 8 February 2023) addressing a design-related weakness in the Diesel Particulate Filter material that can develop hairline cracks over its service life. This isn't a minor administrative recall — a cracked DPF lets unburned particulate matter bypass the filter, which can cause a failed MOT emissions test and potential Clean Air Zone compliance issues. The broader recall (reference KBA 14555R) covers over 1.2 million Ford diesel vehicles worldwide across nearly the entire range, built between 2014 and 2023.
Ford Focus Mk3 Exhaust System: The Part That Announces Its Own Problems
On the Ford Focus Mk3, 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.
Ford Focus Mk3 Exhaust System: Watch: Replacing It
Mk3 ST cat-back fit (upgrade, not like-for-like repair); no plain Mk3 back box video found
OEM Part Number: confirm via VIN — Rear silencer (aftermarket) Bosal 154-211 / Walker 71403
| Rear silencer (back box) — aftermarket | Walker 71403 (680 mm, code 62); Walker 72329 (655 mm, code 62); Bosal 154-211; MTS 01.96160 (780 mm); MTS 01.64280 (700 mm); Polmo 08.574; Izawit 17.311 |
|---|---|
| Centre / intermediate silencer — aftermarket | Walker 22854 (980 mm); Walker 22853; Walker 23210 (990 mm); MTS 01.52160; MTS 01.80300; Bosal 154-459; Bosal 145-001 |
| Front pipe / catalytic converter (DPF on diesels) — aftermarket | Bosal 090-206 (Euro 5/6); Vegaz FK-318AS (Euro 5/6, 740 mm, OBD); BM Catalysts BM91931H (ceramic, Euro 6, with FK91931); JMJ 1091689 (engine codes IQDA, IQDB, MUDA, PNDA); Ernst 761086 (Euro 5, 805 mm); HJS 96 15 5073 (Euro 5/6a/6b) |
| Genuine (OE) numbers quoted | None quoted in catalogue listings — order genuine parts against your VIN |
| Fitment notes | Only JMJ gives engine codes. No petrol/diesel mapping. |
Important: on several Mk3 Focus engines, the catalytic converter is integrated directly into the exhaust manifold as a single unit, rather than being a separate, bolt-in component further down the exhaust. This means a cheap universal aftermarket catalytic converter often can't simply be spliced in — the non-round mounting area where the manifold meets the rest of the exhaust makes it a poor fit without custom fabrication. If your converter has failed, ordering the correct manifold-integrated OEM or direct-fit replacement is usually more cost-effective than attempting a universal fit.
Ford Focus Mk3 Exhaust System: What It Does
Three jobs happen inside the Ford Focus Mk3'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.
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Ford Focus Mk3 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 Ford Exhaust System
The same part, covered across other Ford models.