DTC P0139: O2 Sensor Circuit Slow Response (Bank 1/Sensor 2): DTC Detecting Condition

DTC P0139 DETECTING CONDITION TABLE

Item	Detecting Condition	Possible Cause
DTC Strategy	Monitor HO2S's response rate	Poor connection Faulty HO2S Faulty ECM
Enable Conditions	Engine warm-up sufficiently Engine run time > 60sec Drive at a steady speed between 45-55 mph (72-88 km/h) Engine Coolant > 70°C (158 °F) No disabling faults
Threshold value	The calculated response rate is too slow (out of threshold in ECM)
Diagnosis Time	Continuous
MIL On Condition	2 Driving Cycles