how to fix P0420 code on Ford F-150 14th Generation (2021-2024)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

1. Remove the oxygen sensors:
   • Use an oxygen sensor socket to carefully unscrew the pre-cat and post-cat sensors.
2. Inspect the sensors:
   • Check for contamination or damage. Replace if necessary.
3. Install new oxygen sensors:
   • Apply anti-seize compound on the threads of the new sensors.
   • Torque to specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the catalytic converter:
   • Unbolt the converter from the exhaust system using a socket set.
   • Carefully remove any hangers or brackets holding it in place.
2. Inspect the catalytic converter:
   • Check for physical damage or signs of clogging. Replace if it appears damaged or clogged.
3. Install the new catalytic converter:
   • Position the new converter, ensuring proper alignment with the exhaust system.
   • Bolt it in place and tighten to manufacturer specifications.

4. Clear Codes and Test

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