Selling MOT failure, best options

onomatopoeia99

philgr wrote: »

Emissions - could also be the car was stone cold when tested. The catalyst isn't instantaneous in its effect, they have to be really, and I mean REALLY hot.

Any MOT tester should know this and ensure the cat is fully up to temperature before doing the test, or redo it after futher warming. A couple of years ago it took my garage half an hour before my car would pass emissions, the computer kept saying "perform further engine warming for 300 seconds" and things like that). You could really smell the cat by the end.

Other thing is a leaking exhaust can adversely affect the emissions reading, that happened to me this year. They thought it was the MAF sensor at first, then investigated further, found a loose clamp, replaced it and it passed.