HELP! ETS Off & Check Engine light....

Let me give you some background.

My car has been running fine for quite some time.

Then, on Friday, my dad takes my car to Tires Plus to get a routine oil change. I was a bit overdue for one. They did a courtesy check, and everything was checked off as "acceptable" (ie. antifreeze, coolant hoses, wiper fluid, etc.) with the exception of my steering fluid being dirty. OK, fine.

Within 5 miles of driving the car, my CHECK GAUGES light comes on, then my ANTIFREEZE light comes on, then ETS OFF, then CHECK ENGINE. OK, now I'm freaking out. The temperature gauge was flying to overheating...

On Monday, my dad takes my car back to Tires Plus, and they did 'a little a this, a little a that' - such as replacing the thermostat, flushing out the antifreeze, etc. All lights disappeared after that. They said something about the ETS Off light and Check Engine light being something about a gasket, but the lights went off - so it didn't seem to be an immediate problem.

I drove the car for the first time this morning....after about 20 miles, the ETS OFF and CHECK ENGINE lights come on. WTF????

First - What does it mean?

Second - What is this going to cost me?

Third - Do you think that the people at Tires Plus screwed around with my car?????

Check your Tranny fluid .. this should be an Auto Cavi correct ??

My lights come on and go off all the time. Why would I check the rany fluid?

did you screw around with your IAT? I had a stupid friend put a "speed chip" into his 96 Cavalier and his engine light, ETS OFF, and his transmission all got screwed up. but after he took out the "chip" and drove it a little bit it went back to normal. But this may not be the same thing.