CEL goes on then off

[BUMMER]

I haven't had the chance to bring my H2 into the dealer yet to have any codes read. This is my CEL issue, maybe someone can help me out with this.

- I always fill up on my way down to Atlantic City on the Garden State Parkway (About 100 miles each way). The truck runs great, I arrive to Harrahs Resort with no check engine light, no issues, no problem

- The next morning when I drive home, about 20 miles into it, my CEL comes on, stays on all the way home.

- The following day I start her up and CEL is still on, then I'll drive about 3 miles and the CEL goes away.


This issue has occured the last 3 times I've gone down to Atlantic city, the CEL turns on at the same exact time and goes away the same.
My first assumption would be a loose gas cap, however the CEL goes away without me retightening it.
My 2nd guess would be a bad Catalytic converter, I've already had Bank 2 replaced, but if it were Bank 1 that was going bad then wouldn't the CEL stay on indefinately until the cat was replaced?

I'm stumped

[Camou2]

Don't travel to Atlantic City and problem solved! If it is a fuel cap evap lock issue then I wouldn't expect the CEL to go away without actually clearing the code. Same thing with the catalytic converter. Probably not fuel! CEL indications should not clear themselves for any reason that I am aware of so probably just wait until the next CEL event and get it scanned asap.