how to fix P0135 O2 sensor code on Toyota Highlander XU70 (2020-Present)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Remove the O2 Sensor

• Locate the Bank 1 Sensor 1 O2 sensor, typically found in the exhaust manifold or near the catalytic converter.
• Using an O2 sensor socket, carefully unscrew the sensor counterclockwise.
• Disconnect the electrical connector from the sensor.

3. Inspect and Clean

• Examine the sensor threads for any debris or damage.
• Clean the mounting surface on the exhaust manifold or pipe with a wire brush to ensure a proper seal.

4. Install the New O2 Sensor

• Apply anti-seize compound (if required) to the threads of the new O2 sensor.
• Thread the new sensor into the exhaust manifold or pipe by hand to avoid cross-threading, then tighten with the O2 sensor socket to the manufacturer's specified torque (usually around 30-35 ft-lbs).
• Reconnect the electrical connector securely.

5. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Monitor the O2 sensor signal with a multimeter or scan tool to ensure it operates within the expected range.