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

Solution

1. Preparation

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

Tools Required:

• OBD-II scanner
• Multimeter
• Infrared thermometer
• Socket set
• Torque wrench
• Jack and jack stands

2. Inspect Exhaust System

• Sub-steps:
  1. Raise the vehicle using the jack and secure with jack stands.
  2. Visually inspect the entire exhaust system for cracks, rust, or holes.
  3. Check all exhaust manifold bolts for tightness.
  4. Listen for leaks by starting the engine and feeling for escaping air around joints.

3. Check O2 Sensors

• Sub-steps:
  1. Locate the upstream and downstream O2 sensors on the exhaust system.
  2. Disconnect the electrical connectors from both sensors.
  3. Use a multimeter to check the voltage output of the sensors (typically 0.1 to 0.9 volts for a functional sensor).
  4. Replace any faulty O2 sensors if the readings are outside of specifications.

4. Test Catalytic Converter

• Sub-steps:
  1. Start the engine and allow it to reach operating temperature.
  2. Use an infrared thermometer to measure the temperature at the inlet and outlet of the catalytic converter.
  3. The outlet temperature should be significantly higher than the inlet (generally 100-150°F increase).
  4. If the temperature difference is not adequate, consider replacing the catalytic converter.

5. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust hangers and any bolts securing the catalytic converter.
  2. Carefully remove the old catalytic converter from the exhaust system.
  3. Install the new catalytic converter, ensuring proper orientation and fit.
  4. Torque all bolts to the manufacturer specifications (typically around 25-30 lb-ft depending on the model).
  5. Reattach all exhaust hangers securely.