Can I assume that it is a petrol engine? (You don't think to tell us). I bet you are using the car for short runs only? If so then with the car engine never getting fully warmed up you end up with unburnt hydrocarbons on the lambda sensor in the exhaust system which switches on the warning.
Put decent fuel in the car and take it for a long run. You should find that the depollution warning light goes off after the hydrocarbons have burned off.
If it is a diesel then this won't work.
ChicksFan, April 2015
