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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on electrical components.
• Lift the vehicle using a jack and secure it with jack stands.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use an O2 sensor socket to remove the sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are tightened to the manufacturer’s specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors securely.

3. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust heat shield if applicable, using a socket set.
  2. Disconnect the exhaust pipes connected to the catalytic converter using a wrench, ensuring to keep any gaskets for reuse.
  3. Unbolt the catalytic converter from the exhaust manifold, taking care to support it during removal.
  4. Install the new catalytic converter, ensuring proper alignment and using new gaskets where necessary.
  5. Tighten all bolts to the specified torque values (consult the service manual for exact values).

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the battery terminals securely.
  2. Use an OBD-II scanner to clear the P0420 code from the vehicle’s memory.
  3. Start the engine and allow it to reach operating temperature.