how to fix P0420 code in Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Test Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter.
• Sub-steps:
  1. Reconnect the battery and turn the ignition on without starting the engine.
  2. Use the OBD-II scanner to check the live data of the oxygen sensors.
  3. If readings are erratic or outside specifications, replace the faulty oxygen sensor(s).

3. Check and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary).
• Sub-steps:
  1. If the catalytic converter is determined to be faulty, raise the vehicle securely on jack stands.
  2. Disconnect the exhaust pipes from the catalytic converter using a socket set.
  3. Remove any mounting bolts or clamps securing the catalytic converter.
  4. Remove the old catalytic converter.
  5. Install the new catalytic converter in reverse order of removal, ensuring all gaskets are replaced.
  6. Torque bolts to the manufacturer's specifications.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Test drive the vehicle under various conditions to ensure the problem does not return.