96 sunfire problems

Ok I have a 96 Sunfire which I LOVE! On monday i was pulling out of a parking lot and my car just STOPPED! so we get it into another parking lot and it started up then it wouldnt we thought it might be bad gas, but I dont think thats the case now. Tuesday I went to get my oil changed pulled of and light went off, thought problem was solved. came home Wed morning let my father use my car he says as soon as he cut the car on my check engine light was on. to drives it about 20 miles gets it home to me car is fine he used it agian car shut off, he got it started again. So sorry for the long story but now he thinks its the Air idle control valve. we havent done the code test yet. my question is what are the odds it is that and if not what else could it be? My car has about 130423 miles on it NEVER had any problems please hlp me. Thank you in advance!!!! by the way its a Sunfire sedan SE i believe my engine is a 2.4 THANKS