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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid electrical shorts during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor:
  1. Locate the upstream oxygen sensor (before the catalytic converter).
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  3. Install the new sensor by threading it into place and tightening it to the manufacturer's torque specification (typically around 30 lb-ft).
• Remove the downstream oxygen sensor:
  1. Locate the downstream oxygen sensor (after the catalytic converter).
  2. Repeat the removal and installation process as above.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if necessary).
• Lift the vehicle safely using jack stands.
• Remove the old catalytic converter:
  1. Disconnect any exhaust hangers or brackets attached to the catalytic converter.
  2. Cut or unbolt the exhaust pipes connecting to the catalytic converter, taking care not to damage surrounding components.
  3. Remove the catalytic converter from the exhaust system.
• Install the new catalytic converter:
  1. Position the new catalytic converter in place.
  2. Connect it to the exhaust pipes and secure using bolts or clamps, adhering to the manufacturer's torque specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery.
• Use an OBD-II scanner to clear any stored trouble codes.
• Start the engine and allow it to reach operating temperature.