Possible Causes
Possible causes are:
- Damaged DPFEGR sensor.
- EGR valve stuck open.
- Slow responding DPFEGR sensor.
- Plugged EGR tube.
- EGRVR circuit shorted to ground.
- Plugged EGRVR vent.
- Improper vacuum hose connection.
- Plugged vacuum hoses.
- Damaged EGRVR solenoid.
- Damaged PCM.