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.

Generation covered: this guide is for the third-generation Focus, built 2011–2018 (commonly the 2014–2018 registered examples still in daily use). The newer Mk4 Focus (2018–) uses different part numbers throughout — check your V5C logbook or VIN if you're unsure which generation you have.

Illustration for editorial purposes

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.

What Ford's remedy involves: a free software recalibration to the DPF regeneration process, along with inspection and, where necessary, filter replacement — carried out at no charge at any authorised Ford dealer. Replacement filters carry a genuinely generous 10-year/160,000km warranty. Check your registration at gov.uk/check-vehicle-recalls, and don't ignore a spanner or engine management warning light if you haven't yet had this checked.

The Part That Announces Its Own Problems

Unlike a lot of the parts on this site, this is one where you'll usually hear the fault before you see it — a rattle, a drone, a sudden increase in noise that wasn't there last week. That's actually useful, since it gives you a head start on catching problems early.

Before you buy: exhaust configuration differs significantly by engine size, fuel type and whether your car has a particulate filter. Always confirm against your VIN before ordering.

OEM Part Numbers

Accuracy note: exhaust and catalytic converter part numbers vary significantly by engine — confirm against your VIN before ordering, and note the important fitment issue below before considering a universal aftermarket catalytic converter.

1.0 EcoBoost catalytic converter	Ford OEM: 1766306, 1770958, 1790029, 1843288, 1873837
Other petrol/diesel engines	Different reference — confirm via VIN, as Ford used several distinct exhaust configurations across the range

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.

What It Does

The exhaust system channels burnt gases away from the engine, reduces noise through the silencer, and on most modern cars, treats emissions through a catalytic converter and particulate filter before gases exit the tailpipe. Petrol and diesel versions of the same model often use entirely different systems due to different emissions treatment requirements.

Fitment & Compatibility

Exhaust systems differ substantially between the petrol, hybrid and plug-in hybrid versions of the Focus Mk3, since the hybrid versions integrate differently with the electric motor's contribution to deceleration. Always confirm the exact part fitted to your specific engine and powertrain combination before ordering. Whether you're sourcing a replacement exhaust system for your Ford Focus Mk3 from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying.

Common Faults

Symptoms of Failure

Rattling noise, especially on startup — often a loose or corroded heat shield rather than the exhaust pipe itself, though worth checking both.
Noticeably louder engine noise — points to a hole or split somewhere in the pipe or silencer, typically caused by corrosion.
Visible rust or flaking on the underside — a warning sign of corrosion that will eventually lead to a leak if left unaddressed.
Failed emissions test — can point to a failing catalytic converter or particulate filter rather than the pipework itself.

DIY Replacement Difficulty

Replacing a full exhaust system is a moderate-to-difficult DIY job requiring access to raise the car safely and often penetrating oil to free corroded fixings. Catalytic converter and particulate filter replacement usually requires specific diagnostic equipment afterward to reset fault codes, making that portion of the job better suited to a garage. Expect 2–4 hours for a full system on a home ramp, or less at a garage with the right lift access.

OEM vs. Aftermarket

Reputable aftermarket exhaust systems are widely regarded as a safe, cost-effective alternative to OEM parts for the pipework and silencer sections. Catalytic converters and particulate filters are worth sourcing from well-regarded brands specifically, since counterfeit or substandard versions are a common cause of failed emissions tests and check-engine warnings.

More Ford Exhaust System Guides

The same part, covered across other Ford models.