Does it have to be on to leave a code for a possible reason for very
bad mpg? Usually 16 in city, 15 with AC on, now down to 13 with AC on.
New plugs, clean air filter, correct tire pressure, all things done as
suggested in this group. Just about 40K on it.
I'm taking it in for PA state inspections and I asked them to see if
there's a code in the computer for the bad mpg. They said that if the
Check Engine light didn't come on, there will be no code.
True??