Sensor/System Checks
- Check the Heated Oxygen Sensors (HO2S). The HO2S should respond quickly to different throttle positions. If they do not, check the HO2S for contaminants from the fuel, improper use of RTV, sensors may have a White powdery coating. This will result in a high but false signal voltage (rich exhaust indicated). The Powertrain Control Module (PCM) will reduce the amount of fuel delivered to the engine causing a severe driveability condition.
- Check the Mass Airflow (MAF) sensor and intake air system for proper connections.
- Check the Exhaust Gas Recirculation (EGR) system for proper operation.