I had the gascap message a couple of months ago when I had in fact forgotten to tighten it. Message cleared at next restart. The message came on again yesterday, checked the gascap was OK. Filled her up, made sure the cap was on tight, the message still will not clear. I have had the P0441 EVAP system code a few times this winter, dealer never found any leaks using big or small leak test so they just cleared the code and it would usually stay away for a while.
Am I right in thinking this gascap thing might be related? Seems a few of us have had issues with the evap system and no one seems to know exactly what is going on.
Finally, I may be a little paranoid, but isn't there a little metal flap that covers the gas tank inlet? Mine is wide open when I open the cap, is everyone elses like this?