how to fix the P0420 code on my Ford F-150 Fourteenth Generation (2021-present)

Solution

1. Preparation

• Gather all tools and parts needed for the repair.
• Disconnect the vehicle battery to prevent any electrical mishaps.
• Allow the vehicle to cool if it has been running.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: the upstream (pre-catalytic converter) and downstream (post-catalytic converter) sensors.
2. Use a socket wrench to carefully remove the faulty oxygen sensor(s).
3. Install the new oxygen sensor(s) by threading them into place and tightening them to the manufacturer's specifications (typically around 30 Nm).
4. Reconnect the electrical connectors to the new sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is damaged, loosen the bolts or clamps securing it to the exhaust system using a socket set.
2. Carefully remove the old catalytic converter.
3. Install the new catalytic converter, ensuring all gaskets are in place and secure it using the original bolts/clamps.
4. Torque the bolts to the manufacturer's specifications (typically 40-50 Nm).

4. Final Checks

1. Reconnect the vehicle battery.
2. Clear the P0420 code using the OBD-II scanner.
3. Start the engine and let it idle for a few minutes to check for any exhaust leaks.