how to fix the P0138 code on my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the vehicle battery to ensure safety.

2. Remove the Oxygen Sensor

• Locate the oxygen sensor (usually found in the exhaust manifold or downstream).
• Use an oxygen sensor socket or a wrench to unscrew the sensor from the exhaust pipe.
• Carefully disconnect the electrical connector from the oxygen sensor.

3. Inspect and Clean

• Inspect the wiring harness and connectors for damage or corrosion; repair or replace if necessary.
• Clean the oxygen sensor threads and the mounting area on the exhaust using a wire brush.

4. Replace the Oxygen Sensor

• Install the new oxygen sensor, ensuring that it is screwed in securely but not overtightened (typically 30 ft-lbs torque).
• Reconnect the electrical connector to the new oxygen sensor.

5. Reconnect Battery and Test

• Reconnect the vehicle battery.
• Start the engine and let it reach operating temperature, then check for leaks around the exhaust and verify that the check engine light is off.