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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, with the engine off and cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set.
• Remove the upstream and downstream oxygen sensors:
  1. Locate the O2 sensors on the exhaust system.
  2. Use the O2 sensor socket to unscrew the sensors counterclockwise.
• Install the new sensors:
  1. Apply anti-seize compound to the threads of the new O2 sensors.
  2. Screw in the new sensors by hand, then tighten to the manufacturer's specifications (usually around 30-35 lb-ft).

3. Inspect the Catalytic Converter

• Tools Required: Jack and jack stands, exhaust pipe cutter or saw.
• Check the catalytic converter for physical damage or clogging:
  1. Use a visual inspection to look for dents, rust, or leaks.
  2. If necessary, remove the catalytic converter by cutting the exhaust pipes or unbolting the flanges.
• Test the catalytic converter:
  1. Using an exhaust gas analyzer, check if the converter is functioning correctly.
  2. If it’s inefficient, proceed to replace it.

4. Replace Catalytic Converter (if required)

• Tools Required: Socket set, exhaust pipe cutter, gasket scraper.
• Install the new catalytic converter:
  1. Ensure the mating surfaces are clean and free of debris.
  2. Position the new catalytic converter and secure it with bolts or clamps as per the manufacturer's specifications.
  3. Replace any gaskets that were removed, ensuring a proper seal.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Start the engine and let it run for a few minutes to check for any reoccurrence of the code.