Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2)
The P0158 trouble code appears when the sensor has remained at a high voltage for too long.
This oxygen sensor is located behind the catalytic converter. It sends information to the power control module (PCM) about the efficiency and released oxygen levels of the catalytic converter.
When an engine is running lean, it means that there is more oxygen than fuel in the exhaust gases. When the engine is running rich, it means that there is more fuel than oxygen in the exhaust gases.
If the sensor is working properly it switches from low voltage (high levels of oxygen) to a high voltage (low levels of oxygen).
A mechanic will use an OBD-II scanner to pull all present trouble codes that have been stored by the power control module (PCM).
The live data for the oxygen sensor on the scanner is reviewed. They will check the voltage reading to see if the oxygen sensor switches from low voltage to high voltage every few seconds.
When an engine coolant temperature sensor trouble code is present as well, the live data on the scanner is checked for proper engine temperature.
The wiring of the rear oxygen sensor is checked for shorts, breaks, or exposure.
Test the fuel pressure to see if it is higher than normal.
Run manufacturer diagnosis procedures on the power control module (PCM) to determine whether it needs to be replaced or updated.
The P0158 trouble code is considered serious if it is causing your 2012 Mitsubishi Eclipse spyder to stall out. This problem should be addressed as soon as possible to avoid drivability issues.
An oxygen sensor set and propane tank will be necessary to remove the oxygen sensor if it has ceased in the exhaust or is difficult to reach.