DTC P0139 Acura

Description

If the response time of the rear secondary HO2S becomes longer than the specified time after current to the secondary HO2S heater is applied, a malfunction is detected and a DTC is stored. The execution time is once per driving cycle and the duration time is 20.7 seconds or less. When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the PCM memory. If the malfunction recurs during the next (second) drive cycle, the MIL comes on and the DTC and the freeze frame data are stored. NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot.