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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, torque wrench, multimeter.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) O2 sensors.
  2. Disconnect the electrical connectors from both O2 sensors.
  3. Use the O2 sensor socket to remove the faulty O2 sensors.
  4. Install new O2 sensors and torque them to the manufacturer’s specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter or saw.
• Sub-steps:
  1. Raise the vehicle securely on jack stands to access the exhaust system.
  2. Remove any heat shields or brackets securing the catalytic converter.
  3. Use the exhaust pipe cutter to cut the pipes adjacent to the catalytic converter, if necessary.
  4. Remove the old catalytic converter and install the new one, ensuring proper alignment.
  5. Reattach any heat shields or brackets removed earlier.
  6. Lower the vehicle.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  3. Start the engine and let it reach operating temperature.
  4. Take the vehicle for a test drive to verify that the check engine light does not reappear.