The CEL and Track off lights come on when the gas tank falls below 7/8 full. Fill it up and the lights go off. I have read all of the forums which talk about Oxy sensors or MAF senor or evap canister or solenoid but no one ever says what fixed their issue. Seems to be a vacuum in the gas tank too. Also, may be unrelated, when the headlights are on the ‘R’ (reverse) ligth indicator on the dash stays on even when in ‘D’. Help please. 111,000 miles. Drives perfectly still. Will not pass NC emissions with act codes on OBD I am told.