Left gas cap off - no codes.

[jake75]

I am getting old. Filled up in Cinci area - drive 90 or so miles to Columbus - virtually all interstate. Discovered I never put the gas cap back on. But no check engine code thrown.
Any issues to anticipate going forward?

[trb]

Probably not. From my reading, it only runs the evaporative emissions check involving the gas cap pressurization every so often. If you drove straight through the 90 miles, chances are it did not run the test during that time. I had the check engine light and P0440 code and cleared it on my 03 GT a few days ago, and so far several days later, it still has not run the test yet.

[ImUrOBGYN]

As was mentioned, some codes do not show immediately. Or, it may've stored a temporary code that will probably clear itself later before showing as an engine light. You can always have autozone or one of those kinda stores check and clear any stored or present codes for free or you can disconnect the battery for 10min or so and that should clear them all, as well.

As far as any actual problems deriving from your forgetting the cap, there shouldn't be any consequences.

[ColonelPanic]

Just drive it, you'll be fine.

I suspect the cap seal is degrading on the 2003. Sometimes if I don't put it on just right some OBD-II monitor goes into a 'Not Ready' state after a couple hundred miles. If I remove/reinstall the cap and drive it for some time, everything goes back into a 'Ready' state. None of this is apparent without the ScanGauge.

It has thrown a small evap leak code but that took well more than 90 miles. Clearing the code and remove/reinstall of the cap took care of it.

[jake75]

Thanks to all for the reassurance. I am a neophyte on most things related to motor vehicle issues.