96 Cavalier wierd problem

I have a 96 Cavalier 2.2 3 speed auto that has a strange problem.
Randomly when I hit 3/4 of a tank the check engine light will come on and go away at 1/2 tank or it just stays on. It also burns through fuel during this, about double the consumption. Can anyone help me, thanks.

P.S. just would like to know the problem not really interested in fixing it as this car is only a stop-gap until I get an eclipse in the next few months.

Go to AutoZone or somewhere and have them scan the codes. (the code is still there even after the light goes off)

Could be something as simple as a bad gas cap, or O2 sensor.

i have been thinking about doing that for some time now, and I probably will, thank you