These MOT failure patterns show up more often on this registration year than on similar cars of the same class, age, and mileage.
Shares below are measured across the 495 failed first attempts in 2025 that the age-and-mileage comparison can be computed on.
Standout: Catalyst emissions — 21.8% of this year's failed first attempts
Recorded on 108 of those tests. It tops the table on elevation — about 4.0× more often than on similar cars of the same age and mileage. On this year it is also the commonest failure, so it answers both questions at once. The full ranked list is in the table below.
No patterns met the strongest callout thresholds on this page; showing the highest-lift rows that still cleared the display floors.
| Fault pattern | Location | Failures | vs similar cars | Share of fails | Confidence |
|---|---|---|---|---|---|
|
Catalyst emissions
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Catalyst emissions
|
Any | 108 | ×4.0 | 21.8% | Likely |
|
Component mounting prescribed areas (rear)
Suspension > Component mounting prescribed areas
|
Rear | 83 | ×3.2 | 16.8% | Likely |
|
Emissions not tested
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Emissions not tested
|
Any | 32 | ×3.1 | 6.5% | Likely |
Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and about 2.0× more often than similar cars).