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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, infrared thermometer, socket set, jack and jack stands.
• Ensure the vehicle is on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use a socket wrench to remove the sensors.
  4. Install new oxygen sensors by threading them into the exhaust manifold and catalytic converter.
  5. Reconnect the electrical connectors securely.

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

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Remove the bolts or clamps securing the catalytic converter to the exhaust pipes using a socket set.
  4. Carefully remove the catalytic converter from the exhaust system.
  5. Install the new catalytic converter, ensuring the gaskets are in good condition and secure it with bolts or clamps.
  6. Torque the bolts to the manufacturer's specifications (typically around 30-40 ft-lbs, but refer to service manual for specifics).

4. Reconnect and Reset the System

• 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.