how to fix P0420 code on Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical connections.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: Oxygen sensor socket, ratchet, torque wrench
• If oxygen sensor readings are abnormal:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Use an oxygen sensor socket to carefully unscrew the faulty sensor.
  3. Apply anti-seize compound to the threads of the new sensor.
  4. Install the new sensor and tighten it to the manufacturer’s specified torque (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Wrench set, exhaust pipe cutter, gasket scraper
• If the catalytic converter is damaged or clogged:
  1. Remove any heat shields or brackets connected to the catalytic converter.
  2. Use an exhaust pipe cutter to cut the exhaust pipes on either side of the catalytic converter.
  3. Clean the mating surfaces on the exhaust pipes using a gasket scraper.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  5. Use new gaskets and bolts to secure the catalytic converter, following the manufacturer's torque specifications.

4. Final Steps

• Reconnect the battery.
• Clear the codes using the OBD-II scanner.
• Start the vehicle and allow it to reach operating temperature.