Engine management light problem

[coincatcher]

I own a 2002 Audi TT MK1 which has done 118k

The engine management light keeps coming on after reasonably long journeys for example we drove about 50 miles parked up but no problem.The next day we headed for home and the light came on.

My daughters boyfriend did a diagnostic as he is a trained mechanic and changed the coolant sensor but it keeps coming on after relative short journeys. The gauge needle is the same and engine performance has not changed.

The sensor used was not a genuine audi one could this be the problem ?

Could this be the problem

Many thanks
Mark

 

[NHN]

1st I would test with a genuine, then check wiring, if it still throws a fault.

 

[coincatcher]

Thank you for the reply we will try that route next
Mark