DTC P0139 (RO2_R) - Rear Oxygen Sensor (O2S) Circuit Slow Response
IF DTC P0136 is displayed, perform DTC P0136 testing. If DTC P0136 is not displayed, replace O2S.
IF DTC P0136 is displayed, perform DTC P0136 testing. If DTC P0136 is not displayed, replace O2S.