ok so i just got a 1990 integra with a gsr swap in it the other day i went to run some civic and my check engine light comes on so i stop shut the car off and check everything see nothing turn the car back on lights not on anymore today im driving hit it on time and about two mins later the light comes on stop and check it out nothing again turn the car back on the lights on again what could this be? any help would be great

 

That's too vague for us to help you with.
First step will be pulling the CEL, if you don't know how, use the SEARCH function.
And stop beating on the car til you find out what the CEL is for.

 

oh ok and thanks yeah im not driving it at all

 

the fuel light came on and i have a half a tank of gas and how do you pull the code when the light only comes on when driving ??

 

Well you have to get the CEL to trip again. Next time it does pull over and leave the car on to pull the code.
Could be a misfire or something.