Aside from the gas cap vacuum leak, why would a CEL ever clear itself?
Over the last few months I have had CELs, first for a misfire cylinder 4, which apparently was cured after my plugs were changed at the 60k service. Then I got a CEL for "long term fuel trim" about a month ago for an apparent vacuum leak after the FMIC installation. I've cleared that one twice. Well it reappeared a few days ago, then cleared itself yesterday. Why? How?
I have an idea why, but I'd like to hear the super smart car guys explain it.
Over the last few months I have had CELs, first for a misfire cylinder 4, which apparently was cured after my plugs were changed at the 60k service. Then I got a CEL for "long term fuel trim" about a month ago for an apparent vacuum leak after the FMIC installation. I've cleared that one twice. Well it reappeared a few days ago, then cleared itself yesterday. Why? How?
I have an idea why, but I'd like to hear the super smart car guys explain it.

