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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a flat surface and set the parking brake.
• Disconnect the battery to ensure safety.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  • Disconnect the electrical connector.
• Install the new O2 sensor:
  • Apply anti-seize compound to the threads of the new sensor.
  • Tighten the sensor to the manufacturer's specified torque (typically around 30 ft-lbs).
  • Reconnect the electrical connector.
• Repeat this for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, exhaust pipe cutter, welding kit (if required), torque wrench.
• Remove the catalytic converter:
  • Use the socket set to disconnect the bolts securing the catalytic converter to the exhaust system.
  • Cut the exhaust pipe if it is welded.
• Install the new catalytic converter:
  • Position the new converter and secure it using new gaskets and bolts.
  • Tighten to the specified torque values (usually around 40-50 ft-lbs for exhaust bolts).
• If applicable, weld connections as needed.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear any stored trouble codes.