I am getting code errors of P0455 and P0451
I have a 2004 E320. I just started getting the red check fuel cap error and the check engine light has come on. After scanning for the code errors the first and only code error was P0451 EVAP large leak error. I replaced the gas cap with a Stant cap and cleared out the code. About 2 weeks later, I received the red check fuel cap error and the check engine light came on again. I scanned the codes and receive code errors P0451 again along with P0455. I checked the cap and cleared the codes. A couple of days later, the same errors came back. I have noticed that each time it was after filling the tank driving for about 45 miles and then sitting idle at a long stop light. After the tank gets to about 1/2, I never have an issue.
Looking for a solution, since I am baffled!
Last edited by bcdanzig; Jan 30, 2013 at 08:03 PM.
Reason: added more information on problem