A few weeks ago when I started my car in the morning it stumbled/misfired for about 60 seconds during which the CEL flashed off and on, but then stayed on. The car has not misfired since and I'm getting the same mileage as ever. . While I know that code P301 is supposed to be a cylinder 1 misfire, I have also read that it could be triggered by problems with vapor recapture canister. In my case, the night before had been very warm (and the underground tanks probably still quite cool) and I filled, somewhat topped off, the tank 1/2 mile from home that evening. So I'm wondering if gasoline could have expanded and overflowed into the recapture system and cause the temporary misfire and yet left no permanent damage. I have not yet cleared the code to see if it returns.
Anyone have any similar experience?