P0139

Test 1 - 5:

SYMPTOM
P0139-O2 SENSOR 1/2 SLOW RESPONSE

TEST NOTE
This symptom is diagnosed using the P0133-O2 SENSOR 1/1 SLOW RESPONSE.

WHEN MONITORED
Start and drive vehicle greater than 20 mph and less than 55 mph Throttle open for a minimum 120 seconds. Coolant Temp greater than 70 °C (158 °F) Catalytic Converter Temperature greater than 600 °C.

SET CONDITION
The O2 sensor voltage switches properly from lean to rich during monitoring. Two Trip Fault.

POSSIBLE CAUSES
- Good Trip Equal To Zero
- Exhaust Leak
- O2 Signal Circuit
- O2 Return Circuit
- O2 Sensor