My engine warning light has come on a few times now. The car drives fine and is better on fuel than ever having had a major ford service recently. The light seems to come on if the car is driven then stopped then started again soon after like stopping for petrol, the light comes on straight away but car drives fine. I thought it was the maf sensor so I removed and found grime on it and bought a replacement but still not solved it.

I have checked the test mode on the dash and it says dtc none#?