Test 9: Air Flow Sensor

Warm engine to operating temperature. Check that the sensor is properly installed and firmly seated. Ensure sensor plate moves freely. Pull back rubber covering airflow sensor connector. Turn ignition on.
Ensure 5 volts is present at Gray/White wire. If not, check related circuits. Measure voltage at Gray/Yellow wire. With airflow meter flap closed, it should measure about one volt. As airflow meter flap is moved to wide open, it should steadily increase to 4.5 volts. If not, replace airflow meter.