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 8,172 of 8,176 failed first attempts that recorded an odometer reading in 2025 — the subset the age-and-mileage comparison can be computed on.
Standout: Catalyst emissions — 13.9% of this year's failed first attempts
Recorded on 1,135 of those tests. It tops the table on elevation — about 6.2× 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.
| Fault pattern | Location | Failures | vs similar cars | Share of fails | Confidence |
|---|---|---|---|---|---|
|
Catalyst emissions
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Catalyst emissions
|
Any | 1,135 | ×6.2 | 13.9% | Strong |
|
Exhaust system (front)
Body, chassis, structure > Exhaust system
|
Front | 293 | ×5.6 | 3.6% | Strong |
|
Emissions not tested
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Emissions not tested
|
Any | 247 | ×4.7 | 3.0% | Likely |
|
Exhaust system (rear)
Body, chassis, structure > Exhaust system
|
Rear | 414 | ×4.0 | 5.1% | Likely |
|
Registration plate lamp(s) (rear)
Lamps, reflectors and electrical equipment > Registration plate lamp(s)
|
Rear | 578 | ×3.4 | 7.1% | Likely |
|
Headlamp (front)
Lamps, reflectors and electrical equipment > Headlamps > Headlamp
|
Front | 593 | ×2.5 | 7.3% | Possible |
|
Drive shafts — Joints (front)
Body, chassis, structure > Transmission > Drive shafts > Joints
|
Front | 594 | ×2.1 | 7.3% | Possible |
Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and about 2.0× more often than similar cars).