how to fix P0420 code on Ford F-150 13th Generation (2015-2020)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to avoid electrical shorts.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust manifold and catalytic converter.
2. Using an O2 sensor socket, carefully remove the sensors from the exhaust system.
3. Inspect the sensor connectors for damage or corrosion; clean if necessary.
4. Install new oxygen sensors, tightening them to the manufacturer's specifications (usually around 30 lb-ft).
5. Reconnect the sensor connectors securely.

3. Inspect and Replace the Catalytic Converter

1. If the catalytic converter is found to be faulty during testing, remove it from the exhaust system.
2. Detach any heat shields or brackets holding the catalytic converter in place.
3. Cut the exhaust pipes if necessary to remove the old converter, ensuring proper alignment when re-installing.
4. Install the new catalytic converter, securing it with new gaskets and bolts, torquing to the manufacturer's specifications (typically around 40 lb-ft).
5. Reattach any heat shields or brackets.

4. Clear Codes and Test Drive

1. Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
2. Start the engine and allow it to reach operating temperature.
3. Take the vehicle for a test drive to ensure the check engine light does not reappear and monitor performance.