DME 7.8

P0139

02 Sensor Circuit Slow Response

Diagnostic conditions
- Air mass between 25 kg/h and 120 kg/h
- Oxygen sensing after catalytic converter is active
- Basic adaptation has reached steady condition
- No secondary air diagnosis
- No fuel tank ventilation diagnosis
- EVAP canister not highly loaded
- No other oxygen sensor faults

Possible cause of fault
- Oxygen sensor faulty

Diagnosis/troubleshooting

NOTE: Do not use contact spray on the oxygen sensor plug connections as this may cause irreparable damage to the wiring (contamination of the oxygen sensor via the reference air channel).