P0138

The P0138 code indicates that the oxygen sensor circuit for bank 1 has a high voltage signal, which may lead to poor engine performance and increased emissions in the 2020-present Toyota Highlander.

The P0138 code indicates a high voltage signal from the oxygen sensor in the exhaust system of a 2020-present Toyota Highlander. This typically points to an issue with the sensor or its circuit.

The Toyota Highlander is displaying a P0138 trouble code, indicating a problem with the oxygen sensor circuit in bank 1, sensor 2. This generally means that the sensor is detecting a voltage that is higher than expected.

The P0138 code on a 2014-2019 Toyota Highlander indicates that the Engine Control Module (ECM) has detected a high voltage signal from the oxygen sensor circuit, specifically for the downstream oxygen sensor (Bank 1).

The P0138 code indicates that the oxygen sensor circuit for Bank 1 Sensor 2 on your 2014-2019 Toyota Highlander is experiencing a high voltage condition.