> Everything tested during an MOT (except emissions, which I've never seen fail)
Don't think this is true, I was looking at the MOT record of a car a few days ago and emissions failure was definitely stated as MOT failure reason.
Don't think this is true, I was looking at the MOT record of a car a few days ago and emissions failure was definitely stated as MOT failure reason.
They're getting a lot more strict on ECU testing, too. Used to be you just needed to have no check emissions codes being thrown. Now they're more thorough, for most ECUs they can check to also verify no modifications to the emissions settings (can't just tell the computer it has no cat so it doesn't throw codes).
Hydrocarbons 0.023/1.2 (1:50) CO 0.3/15 (1:50) CO2 502/NA (guess this one has no limit?) NOx 0.081/2 (1:25)
Maybe some states apply newer, stricter limits to older cars retroactively but in my experience as long as a car is operating normally it is impossible to fail emissions. I wouldn't be surprised if the ECU threw a code before the dynamo test caught something. IMO the most practical check they actually do is the presence of a functioning gas cap.
Even that throws a code these days. 14y.o. BMW has a pump that pressurizes the fuel system to check for leaks and it’s usually the pump that breaks and throws a code.
17y.o. Corolla threw a fuel system code but it was the gas cap.
Only thing is that this pressurization check system only runs when the weather is warm enough, so resetting a code usually lets you pass e-testing as “Not Ready” because months can go by. Maybe there’s differences in summer/winter e-testing criteria.
The next year emissions weren't an issue, mainly because the only journey it did was a 250 mile run up the A1/A66/A6 and back again on a weekly basis.