DTC P0158 (2019): General Description
The front secondary heated oxygen sensor (secondary HO2S (bank 2, sensor 2)) detects the oxygen content in the exhaust gas downstream of the front warm up three way catalytic converter (WU-TWC) (bank 2) during stoichiometric air/fuel ratio feedback control. The powertrain control module (PCM) controls the air/fuel ratio from the front air/fuel ratio (A/F) sensor (bank 2, sensor 1) output voltage to optimize the front WU-TWC (bank 2) efficiency. When power is applied to the front secondary HO2S (bank 2, sensor 2) heater, if the front secondary HO2S (bank 2, sensor 2) output continues to exceed the upper limit used during feedback control, the PCM detects a malfunction and stores a DTC.