MOT failure · RFR #31842
Emission control equipment fitted by the manufacturer missing, obviously modified or obviously defective
Total
23
Models
2
Models most at risk.
Ranked by rate, not raw volume. A Fiesta shows every failure a lot because there are a lot of Fiestas. Rate = share of that model's own MOTs.
Cost orientation
Hard to predict in isolation — depends what's actually worn.
This defect doesn't map to a clean retail-part swap; ranges vary too widely without seeing the car. Use the estimator to bracket the all-in cost across the items most likely to surface alongside it.
Open estimator
Frequently asked.
- Why does emission control equipment fitted by the… fail an MOT?
- Emission control equipment fitted by the manufacturer missing, obviously modified or obviously defective. Most commonly flagged on the Nissan GT R. The DVSA's MOT standards require this item to meet minimum safety thresholds — when it falls short, the tester logs it as a Major or Dangerous defect and the car fails outright.
- How much does it cost to fix emission control equipment fitted by the…?
- Costs vary depending on the vehicle, region, and severity. Use our MOT cost estimator for typical UK garage rates across the most common failure items.