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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, ratchet, and torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the wiring harness from each sensor.
  3. Use the O2 sensor socket to remove the sensors from the exhaust system.
  4. Install the new sensors by threading them into the exhaust system.
  5. Torque the sensors to the manufacturer’s specified value (usually around 30 lb-ft).
  6. Reconnect the wiring harness to each sensor.

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

• Tools Required: Socket set, cutting tool (if needed), exhaust hangers removal tool.
• Sub-steps:
  1. Raise the vehicle safely using jack stands.
  2. Remove the exhaust hangers that hold the catalytic converter in place.
  3. Disconnect the exhaust pipes from the catalytic converter. This may involve cutting if bolts are seized.
  4. Remove the catalytic converter from the vehicle.
  5. Install the new catalytic converter, ensuring proper alignment with the exhaust system.
  6. Secure with new gaskets and bolts, torquing to manufacturer specifications.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Test drive the vehicle for at least 30 minutes under various driving conditions to ensure the check engine light does not reappear.