how to fix P0138 code in my Toyota RAV4 XA40 (2013-2018)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the ignition off and the engine cool.
• Disconnect the negative battery terminal to prevent any electrical issues.

2. Inspect and Replace Oxygen Sensor

1. Locate the Oxygen Sensor: Find the Bank 1 Sensor 2 oxygen sensor in the exhaust system, typically located downstream of the catalytic converter.
2. Disconnect the Sensor: Carefully unplug the electrical connector from the oxygen sensor.
3. Remove the Sensor: Use an oxygen sensor socket or a wrench to unscrew the sensor from the exhaust pipe.
   • Tools Required: Oxygen sensor socket, wrench, penetrating oil (if necessary)
   • Safety Warning: Use caution if the exhaust system is hot; allow it to cool before handling.
4. Install New Sensor: Apply anti-seize compound to the threads of the new oxygen sensor (if recommended) and install it by hand to avoid cross-threading.
5. Torque the Sensor: Use a torque wrench to tighten the oxygen sensor to the manufacturer’s specifications (usually around 30-40 lb-ft).
6. Reconnect the Electrical Connector: Firmly plug the connector back into the new oxygen sensor.

3. Clear Error Codes

1. Reconnect Battery: Reconnect the negative battery terminal.
2. Clear Codes: Use the OBD-II scanner to erase the P0138 code from the ECM.

4. Perform a Test Drive

• Drive the vehicle under various conditions to allow the ECM to monitor the new sensor and ensure the check engine light does not reappear.