Dangerous MOT Failures - Nuisance  and Environmental Hazards

Part of the  Dangerous MOT Failures Explained series.

While often overlooked, nuisance-related faults - like excessive exhaust smoke or noise - can still result in a 'Dangerous' MOT fail. 

During an MOT Test these issues often indicate poor maintenance or mechanical faults.

There are 3 dangerous MOT fail items listed under nuisance. They must be corrected before the car can legally return to the road.

Full List of Dangerous MOT Failures: Nuisances and Environmental Hazards

Nuisance – What to Do If You Fail for This Issue

Failing due to nuisance issues like excessive smoke or noise typically means a deeper mechanical fault is present (e.g., exhaust failure, emissions system damage).

You’ll need a proper diagnostic and repair.

Driving with this fault is illegal and may result in penalties under emissions and noise regulations.

Nuisance – Symptoms to Watch For

• Loud, irregular engine or exhaust noise
• Visible black or blue smoke from exhaust
• Persistent smell of fuel or oil
• Failed emissions tests
• Rattling from the exhaust system

While these might not seem urgent, they can signal serious underlying issues. If your car is unusually loud or smoky, book a garage check before the MOT.