Chevrolet: ETS Off / Check Engine Light, coolant level, light orange

Question
I just had a complete tuneup done on my 1996 Cavalier 2.2L 2 weeks ago. However the ETS Off light and Check Engine Light (orange) just came on at the same time. Mileage is at 155,600 miles and the car is running great. No stalling or sputtering, RPMs are good, engine temp ok, coolant level ok, oil pressure ok. Is this a loose connection/emmissions sensor etc. Please advise before my mechanic takes me for a ride!

Answer
Rino;
 Hi first off-I would take it right back to the guys that did the work-if all of that was done the  . But the light can come on for a lot of things, even if the gas cap is off it can come on, so it can be many things.I wonder if it just came on due to the tune up.If they put the computer on it they should have seen all of the codes that it would have put out,so if something was wrong they would have told you.It might be a simple thing.I would have it checked.  ok >>>