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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a flat surface and secure with wheel chocks.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors of both sensors.
  3. Remove the sensors using the O2 sensor socket and ratchet.
  4. Install new oxygen sensors, tightening to the manufacturer's specifications (typically 30-40 lb-ft).
  5. Reconnect the electrical connectors.

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

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed), gaskets
• Sub-steps:
  1. Remove any heat shields covering the catalytic converter.
  2. If necessary, cut the exhaust pipe using an exhaust pipe cutter to remove the old catalytic converter.
  3. Install the new catalytic converter, ensuring that any gaskets are replaced and that it is oriented correctly.
  4. Bolt the exhaust system back together, tightening all connections to specification (typically 25-30 lb-ft).
  5. Reinstall any heat shields that were removed.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not reappear.