Originally Posted by
budwich
what was / is the code???? and how are the codes being read??? The interpretation of the code is very important but without the code, you are asking the forum to "guess" at your interpretation. Other than that, issues like "unusual gas mileage conditions" even without a CEL light may indicate problems that need further analysis. Any previous CEL light codes might have been misinterpreted leaving root conditions undiagnosed.
OBDII, get one at your local auto parts store.