Check Engine Light on when tank is about 1/2 empty
 

My check engine keeps coming on when my gas gets down to about 1/2 tank. I filled the tank up and cleared the check engine light by unpluging the neg battery cable for a few minutes. The light came back on when the fuel level got back to about 1/2 tank empty. Can some one please explain to me what's going on and how to resolve this.

Gas cap on tight?

as tight as it would go. The gasket looks a little worn.

try replqacing the gas tank cap, its a cheap try to fix the problem , or here is a wild idea,,,,,read the code and see where that leads...

Thanks. I bought the cap and cel went away.

Woohoo!

darn light keeps coming back. i change the gas cap. small evap leak.

Check the vac lines as a starting point...