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 during repairs.
• Lift the vehicle and secure it on jack stands.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Use an oxygen sensor socket to unscrew the old sensors.
  3. Apply anti-seize compound to the threads of the new oxygen sensors.
  4. Install the new sensors and tighten to manufacturer specifications (typically around 30-40 ft-lbs).
  5. Reconnect the wiring harness to each sensor.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove any heat shields or brackets obstructing access to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust pipes using a socket set; note the orientation for reinstallation.
  3. Inspect the old catalytic converter for signs of damage or clogging.
  4. Install the new catalytic converter, ensuring it is oriented correctly and properly aligned with the exhaust system.
  5. Torque the bolts to manufacturer specifications (typically around 30-40 ft-lbs).

4. Final Checks

• Sub-steps:
  1. Reinstall any heat shields or brackets removed during the repair.
  2. Reconnect the battery.
  3. Clear the P0420 code using the OBD-II scanner.