my Ford F-150 12th Generation (2009-2014) has a check engine light with P0135 code

Learn how to diagnose and fix P0135 oxygen sensor circuit malfunction in Ford F-150 (2009-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Remove the Oxygen Sensor

• Locate the bank 1 sensor 1 oxygen sensor, typically found in the exhaust manifold or upstream of the catalytic converter.
• Use a 22mm oxygen sensor socket or wrench to carefully unscrew the sensor from the exhaust system.
• Disconnect the electrical connector by pressing the release tab and pulling it apart.

3. Inspect and Clean

• Inspect the threads of the oxygen sensor and the mounting hole for carbon buildup or damage.
• Clean the threads of the exhaust pipe with a wire brush if necessary to ensure a proper seal.

4. Install New Oxygen Sensor

• Apply anti-seize compound on the threads of the new oxygen sensor (if applicable).
• Screw the new sensor into the exhaust system by hand to avoid cross-threading, then tighten to manufacturer specifications (usually around 30 lb-ft).
• Reconnect the electrical connector until it clicks securely into place.

5. Final Steps

• Reconnect the negative battery terminal.
• Start the engine and let it run for a few minutes to ensure there are no leaks and the sensor is functioning properly.