how to fix P0135 O2 sensor code on Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather tools and parts required.
• Park the vehicle on a flat surface and ensure the engine is cool.
• Disconnect the negative battery terminal to avoid electrical shock.

2. Remove the Oxygen Sensor

• Locate the upstream O2 sensor (typically found on the exhaust manifold).
• Use a socket wrench (22mm O2 sensor socket recommended) to carefully unscrew the O2 sensor.
• Disconnect the electrical connector from the O2 sensor by pressing the release tab.

3. Inspect and Clean

• Inspect the threads of the O2 sensor and the exhaust manifold for carbon deposits and rust.
• Clean the threads with a wire brush if necessary.

4. Install New Oxygen Sensor

• Apply anti-seize compound (if required) to the threads of the new O2 sensor to facilitate future removal.
• Screw the new O2 sensor into the exhaust manifold and tighten to manufacturer specifications (usually around 30 ft-lbs).
• Reconnect the electrical connector securely.

5. Reset the Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0135 code from the ECM.
• Start the engine and let it run for a few minutes to ensure proper operation.