Component Inspection

Engine Control
P2251 O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) - Inspection/Repair:_:Component Inspection

Component Inspection

1. Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a bad false voltage signal.
If contamination is evident on the HO2S, replace contaminated sensor with the new one and go to next step.
2. Is sensor contaminated?