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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety.
• Raise the vehicle using a jack and secure it on jack stands.

2. Inspect and Replace the Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors:
  1. Disconnect the electrical connectors from the oxygen sensors.
  2. Use the O2 sensor socket to remove the sensors from the exhaust manifold and catalytic converter.
• Install the new oxygen sensors:
  1. Apply anti-seize compound on the threads of the new sensors.
  2. Install the upstream sensor first, then the downstream sensor, tightening to the manufacturer’s specified torque (typically around 30-40 lb-ft).
  3. Reconnect the electrical connectors securely.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Wrench set, exhaust pipe cutter, gasket scraper, new gaskets
• Remove the old catalytic converter:
  1. Disconnect the exhaust pipes from the catalytic converter using a wrench.
  2. If necessary, use an exhaust pipe cutter to cut the pipes.
  3. Remove any mounting brackets or heat shields.
• Install the new catalytic converter:
  1. Place the new catalytic converter in position and secure it with new gaskets.
  2. Reconnect the exhaust pipes, ensuring tight seals.
  3. Reinstall any heat shields or brackets.

4. Reconnect Battery and Test

• Reconnect the battery and start the engine.
• Check for leaks around the exhaust system and ensure everything is secure.
• Clear the P0420 code using an OBD-II scanner and take the vehicle for a test drive.