I have had mine off and on for the last couple of months, sometimes right at startup, sometimes while driving and so on...
I just reset it with my Scangage, and since this problem seems to be an emissions issue more than anything, I ignored it, and guess what....hasn't been in about2 weeks, and I am well into my second tank since then. So it could be from over filling and I just had to wait for the canister to dry out?