Originally posted by unisys12:
Gosh I know this is going to sound stupid and I don't mean for it too, but did you make sure that your gas cap was tight after your fill-up? If the cap is not tight (it has to click for it to be tight), this can cause the Emission Control System to signail a false system malfunction and throw up the CEL. I am not overly sure about what codes it would possibly throw up though.
You are correct about a loose or faulty gas cap being the number 1 cause for a particular CEL code.
It would throw an evaporative control system leak code. (440 or 442)
However lean codes are not related. Lean codes are normally caused by intake leaks, fuel problems, and just tired O2 sensors.
