how to fix the P0420 code in my Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather required tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use a socket wrench to remove the oxygen sensors.
3. Inspect the threads and connectors for damage.
4. Install new oxygen sensors and torque to manufacturer specifications (typically around 30-40 ft-lbs).
5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

1. Remove the exhaust pipe bolts securing the catalytic converter.
2. Carefully lower the catalytic converter, ensuring not to damage any surrounding components.
3. Inspect the old catalytic converter for signs of damage or clogging.
4. Install the new catalytic converter, ensuring proper alignment.
5. Torque the exhaust pipe bolts to manufacturer specifications (typically around 25-35 ft-lbs).

4. Clear Codes and Test

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the engine and let it reach operating temperature.
4. Perform a test drive to monitor for any reoccurrence of the code.