MAP Sensor
If ECM senses higher than normal manifold pressure (low vacuum) system can go rich. Disconnecting MAP sensor allows ECM to substitute a fixed value for MAP sensor. If rich condition disappears, replace MAP sensor and continue testing.
If ECM senses higher than normal manifold pressure (low vacuum) system can go rich. Disconnecting MAP sensor allows ECM to substitute a fixed value for MAP sensor. If rich condition disappears, replace MAP sensor and continue testing.