how to fix P0420 code on Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Oxygen Sensors (if faulty)

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Using an O2 sensor socket, carefully remove the faulty sensors.
3. Apply anti-seize compound to the threads of the new sensors.
4. Install the new oxygen sensors and tighten them to the manufacturer's specification (usually around 30 Nm).
5. Reconnect the electrical connectors to the sensors.

3. Replace Catalytic Converter (if necessary)

1. Remove any heat shields or mounts securing the catalytic converter.
2. Use a socket set to remove the bolts connecting the catalytic converter to the exhaust pipes.
3. Carefully lower the catalytic converter from the vehicle.
4. Install the new catalytic converter by reversing the removal process, ensuring to use new gaskets as needed.
5. Torque all bolts to the manufacturer's specifications (typically around 40-50 Nm).

4. Reconnect Battery and Clear Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.
3. Start the engine and allow it to reach operating temperature.

5. Test Drive

1. Take the vehicle for a test drive to ensure the check engine light does not reappear.
2. Monitor the vehicle for any signs of poor performance or unusual behavior.