SULEV EX Model

DTC P0139: Slow Response in Secondary HO2S (Sensor 2) Circuit
1. Do the PCM Reset Procedure.
2. Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Accelerate using wide open throttle. The decelerate for at least 3 seconds with throttle completely closed.
4. Check the Secondary HO2S (Sensor 2) output voltage with the scan tool.
Does the voltage stay at 0.3 V or more?
YES Replace the Secondary HO2S (Sensor 2).
NO-Intermittent failure, system is OK at this time. Check for poor connections or loose wires at C204 (located under the right side of the dash), C102 (located under the under-hood fuse/relay box), the Secondary HO2S (Sensor 2) and the PCM.