Exhaust and emissions MOT failures
Exhaust and emissions faults account for 6.9% of MOT failures. What the tester checks, why cars fail, and which models fail this most.
What are exhaust and emissions MOT failures?
Exhaust failures cover leaks, insecure mountings and emissions over the limit. A blowing exhaust, a failed lambda reading or a diesel that smokes beyond the limit will fail.
How common are exhaust and emissions MOT failures?
Exhaust and emissions faults account for 6.9% of all recorded MOT failures, making them the seventh most common reason cars fail. That share is drawn from the categorised defect records of 16,764 car models in the DVSA data.
| Failure area | Share of all failures |
|---|---|
| Exhaust & emissions | 6.9% |
Which cars fail most on exhaust and emissions?
These models lose the largest share of their own MOT failures to exhaust and emissions items. The percentage is the portion of each model's failures that fall in this area, among models with a large test sample.
| Model | Share of its failures | Overall failure rate | Tests |
|---|---|---|---|
| Mitsubishi Chariot | 40.7% | 34.5% | 6,290 |
| Ferrari F355 | 40.2% | 11.8% | 19,847 |
| Tvr Cerbera | 38.2% | 20.8% | 16,035 |
| Mitsubishi Ralliart | 36.8% | 30.2% | 23,857 |
| Mitsubishi Evo | 36.4% | 18.5% | 8,479 |
| Toyota Town | 35.8% | 35.1% | 6,480 |
| Rover Metro | 35.5% | 37.1% | 278,208 |
| Mitsubishi Fto | 35.4% | 36.0% | 55,526 |
| Mazda Rx-7 | 35.2% | 24.8% | 26,750 |
| Toyota Townace | 34.5% | 32.5% | 12,047 |
| Daihatsu Grand Move | 33.9% | 30.7% | 40,031 |
| Mitsubishi 3000 | 33.8% | 30.2% | 22,804 |
| Rover 214 | 33.7% | 32.4% | 1,034,342 |
| Alfa Romeo 155 | 33.7% | 38.4% | 13,890 |
| Kia Pride | 32.7% | 39.0% | 75,055 |
Other MOT failure areas
How the other DVSA failure areas break down, each with the models that fail it most.
Sources: DVSA MOT History API: MOT test results and defect data ยท DVSA MOT testing data for Great Britain