2021 Ford Focus 1.5L Diesel · LB70 YYG

A persistent concern with this 2021 Ford Focus is the recurring engine management and emissions issue, which has surfaced across two of the most recent tests and represents the single most significant mechanical risk in the record. The 2024-11-20 failure recorded a Major defect for the engine MIL (Malfunction Indicator Lamp) being inoperative or indicating a malfunction, and although the vehicle passed the following day, a similar Major defect reappeared at the 2025-12-11 test, this time accompanied by an explicit dashboard warning that the exhaust filter was full, indicating a diesel particulate filter (DPF) concern. The most recent test on 2025-12-20 resulted in a pass, but the cluster of DPF-related Major defects within a twelve-month window suggests an unresolved or intermittently recurring emissions management fault rather than a one-off anomaly, and this is the area that warrants the closest scrutiny. Recorded mileage of 30,949 miles over a five-year period equates to approximately 6,190 miles per year, which is broadly typical for a vehicle of this age and provides no immediate cause for concern regarding underuse or excessive wear. The mileage progression between tests is also steady, with no significant gaps that would imply extended periods off the road. While the annual figure is not high, diesel-engined vehicles used predominantly for short journeys are particularly susceptible to DPF saturation, as the filter relies on sustained higher running temperatures to regenerate; the fact that DPF issues have already been flagged twice means the actual usage pattern has evidently included enough short-trip operation to compromise filter regeneration, regardless of the otherwise moderate annual mileage. A prospective buyer should treat the diesel particulate filter as the primary area of investigation. The vehicle should be driven on a prolonged mixed route, ideally including at least 20 to 30 minutes of sustained higher-speed running, and the dashboard should be monitored for any reappearance of the exhaust filter full warning, the glow plug or coil symbol, or any new engine management illumination. It would also be prudent to confirm whether the DPF has been subject to a forced regeneration, a professional clean, or a replacement since the 2025 advisory, and to obtain documented evidence of this. On a test drive, listen for any rough idle, misfire, or hesitation under load, and check for excessive soot when starting from cold, all of which can indicate incomplete DPF regeneration or underlying injector issues. Beyond the DPF, the advisory items recorded in the MOT history offer useful direction for a physical inspection. Tyre wear close to the legal limit was noted on the nearside front and rear in January 2024, and screws or nails were recorded in the nearside and offside rear tyres in late 2025, so all four tyres should be examined for age-related cracking, uneven shoulder wear, and the depth of any repairs. Under the vehicle, the test drive should be used to listen for knocks or clonks from the suspension, particularly over speed bumps and uneven surfaces, and to feel for any pulling, vibration, or looseness in the steering, as the Focus is known for wear in front suspension bushes, anti-roll bar drop links, and wishbone components. Finally, with the engine running, watch for any blue or black smoke from the exhaust and note whether the cooling fan cycles correctly, both of which can provide further evidence of the emissions-related concerns already documented in the test record.