O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
The computer is seeing too much voltage from the downstream oxygen sensor on bank 1. This usually means the sensor is faulty, the wiring is damaged, or the exhaust has an issue affecting the reading.
The vehicle will often still run, but fuel economy and emissions can be affected. If the check engine light is flashing, the car runs poorly, or you smell fuel, stop driving and diagnose it right away.
P0138 means the powertrain control module has detected a high-voltage condition in the Bank 1 Sensor 2 oxygen sensor circuit. Bank 1 Sensor 2 is the downstream O2 sensor, located after the catalytic converter on the side of the engine with cylinder 1. The code can be set by a failed sensor, wiring short to voltage, connector problems, or a catalytic converter or exhaust condition that affects sensor readings.
It is a downstream code. Bank 1 Sensor 2 is the oxygen sensor after the catalytic converter.
Yes, but it is less common than a bad sensor or wiring problem. The converter should be tested before replacement.
No. Wiring damage, connector problems, exhaust leaks, and engine running issues can also cause the code.
Usually yes for short trips, but it should be diagnosed soon because fuel economy and emissions can be affected.