2A MAP Sensor Circuit (Codes 13 and/or 14)

1. Turn ignition Off, then tee a vacuum gauge into MAP sensor vacuum line.
2. Start engine, then observe vacuum gauge at idle and while snapping throttle open and closed.
3. If vacuum gauge is reading manifold vacuum at idle and immediately drops to zero when throttle is snapped open, proceed to Test 2 step B.
4. If vacuum gauge indicates zero vacuum at idle, repair vacuum line to throttle body.
5. If vacuum gauge slowly drops to zero when throttle is snapped, repair restriction in vacuum supply line to MAP sensor.