M/T Model

DTC P0139: Slow Response in Secondary HO2S (Sensor 2) Circuit - M/T Model

1. Reset the ECM.
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. Check the Secondary HO2S (Sensor 2) output voltage at 3,000 rpm with the scan tool.

Does the voltage stay within 0.3 - 0.8 V for two minutes?

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 left side of dash), C102 (located at the left side of the engine compartment), the Secondary HO2S (Sensor 2) and the ECM.