P0139

Test 1 - Test 5:

SYMPTOM
P0139-O2 SENSOR 1/2 SLOW RESPONSE

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

WHEN MONITORED
Vehicle is started and driven between 20 and 55 MPH with the Throttle open for a minimum of 120 seconds. Coolant greater than 70° C (158° F). Catalytic Converter Temp greater than 600° C (1112° F) and EVAP Purge is active

SET CONDITION
The oxygen sensor signal voltage switches less than 16 times from lean to rich within 20 seconds during monitoring. Two Trip Fault.

POSSIBLE CAUSES
- Good trip equal to zero
- Exhaust leak
- O2 signal circuit
- O2 return circuit
- O2 sensor