No fuel cap – problems?

[TObject]

I was running my TJ with the fuel cap opened for a whole day. Did I screw anything up? Do I need to do anything now?

[Ace!]

Did your check engine light come on? In Oregon we don't pump our own gas, and the 'attendants' have left the cap un-tightened on a few occasions on our 2001 XJ. It seems to trigger our check engine light due to loss of vacuum or some such thing. I've had the dealer clear the code and asked the service guy about it because it seemed common that attendants did it. The service guy said it won't "do" anything to have the cap off, except trip the light and maybe affect fuel mileage. He said if you tighten the gas cap and drive around long enough the light will go out, but it will be 'stored' until you get a scan tool that clears codes.

Áron O'Proinntigh is ainm dom

[TObject]

My Check Engine light comes on here and there on occasion. I hit the dashboard under the right corner of the instrument panel and it goes off. I did not notice if it came on today or not, I will check on the way home.