how to fix P0135 code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shocks.

2. Inspect Wiring and Connectors

• Visually inspect the wiring harness and connectors for Bank 1 Sensor 1.
• If damaged, repair or replace the wiring and connectors as necessary.
• Ensure all connections are secure and free from corrosion.

3. Replace the Oxygen Sensor

1. Locate the oxygen sensor on the exhaust manifold or front pipe.
2. Use an oxygen sensor socket or a wrench to carefully unscrew the old sensor.
3. Apply anti-seize compound on the threads of the new oxygen sensor to prevent seizing.
4. Install the new oxygen sensor, tightening it to the manufacturer’s recommended torque specification (usually about 30-40 Nm).
5. Reconnect the electrical connector to the new sensor.

4. Check and Replace the Fuse (if necessary)

• Locate the fuse box and identify the fuse for the oxygen sensor heater circuit (consult the owner’s manual).
• Inspect the fuse; if blown, replace it with a fuse of the same amperage.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear any stored codes.
• Start the engine and allow it to reach operating temperature.