Thread: PO542 code on fillup

I'm seeing a PO452 code being thrown everytime I fill up the gas tank, and then by the time I run down below 1/2 tank the check engine light goes away and the code is gone. But it comes back once I fill up again. I replaced the gas cap which didn't help. Any ideas???
Also on a related note it takes a while for the car to start if I let it sit overnight compared to if I make a stop somewhere for a few minutes...almost as if the gas line slowly depressurizing as it sits
please help
Thanks