P0455 2004 Cavalier

Has anyone had any success finding and fixing a P0455 on an 04 Cavalier? I keep getting the light once per fillup. I don't overfill and crank down the gas cap tight on each fillup. I just replaced the gas cap with another OEM cap and am waiting to see if the light comes back on. If it does I'll post an update to this thread. I was just curious as to what others have found wrong when they received this code.

The light came back on. The gas cap replacement apparantly did no good. Anyone have any ideas/suggestions?

Other than a gas cap, it might be related to an evap pump or purge valve.
I suggest you get someone to force an evap system test on the car to see where it's failing from.

I had a PO455 code replaced gas cap made no change. I did a smoke test and it was a bad canister vent valve.it comes from over filling the gas tank. when you replace the vent valve also replace the purge valve in the engine compartment you ca get both at rock auto .com for 18 dollars each.good luck let me know how you made out.:)

P0455 is a large leak in the EVAP system.....a smoke test with the system sealed would easily find it.....

i've had my car into the mechanic twice for this same thing too... will an evap leak cause a hesitation?