NCT emissions warning light

beauf

Someone in the family has NCT booked for tomorrow but an emissions warning light has come on in their petrol car.

Car is not down on power though its seems to hunt a tiny bit on idle. I'm guessing it's just sensor.

Can they do the NCT though?

coldfire1x

Yes, if there's no real issue it will pass.

I had warning lights on last year. Passed without any issue.

beauf

Grand thanks

Leonard Hofstadter

As long as the emissions are not out of spec it will be fine to present it to the NCT.

Be careful, though, for some cars the light only comes on when there is a problem with the exhaust emissions, other faults will get logged to the ECU but they won't put the light on - for example if one of the post cat O2 sensors went in a petrol engined BMW then the light won't come on but if you do a diagnostic scan it will tell you that the ECU has logged a fault with the sensor.

Regardless of whether the car passes the NCT, it still needs to go to a garage - the light is on because there is a problem.

beauf

It will be as soon as they open. The NCT is before that though.

Toyotafanboi

Yeah, the light in itself isnt a fail with a petrol engine car. Definitely do the test anyway.