P0455 Other Causes? Funky

[Pushbutton]

:chickdance:
Twice in the last several weeks my wife's '05 Magnum RT has kicked out P0455 codes. In both cases she (to my everlasting surprise) checked the gas cap and it was tight. The cap is an OEM 1/4 turn, snap into place design.

The last time it happened it was two days after the last refueling.

I have a dealer visit tomorrow for that and an oil change.

What other causes other than a potentially defective gas cap can kick the P0455 code so that I can lead the dealer to a solution other than "could not replicate problem"?

[sound&security]

bad vapor canistor valve [maybe]

[EmagdniM]

Check the hoses. I know in my Dakota I had this code come up a few times and it turned out to be dry rotting on the evap hoses coming into the throttle body...could be the cause.

[Pushbutton]

Well the visit is over. They could not replicate the condition, so, being a good dealer they replaced the fuel cap p/n 5278632AG @ no charge due to extended warranty. I guess I could not ask for better!