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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool completely before starting any work.

2. Inspect and Repair Exhaust Leaks

• Tools Required: Socket set, exhaust pipe sealant
• Visually inspect all joints and connections in the exhaust system for leaks.
• Tighten any loose connections and apply exhaust pipe sealant where necessary.
• Recheck for leaks after repairs.

3. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
• Locate the upstream and downstream oxygen sensors.
• Disconnect the electrical connectors and remove the sensors using an O2 sensor socket.
• Install new sensors by inverting the removal process, ensuring to torque them to manufacturer specifications (typically around 30-40 ft-lbs).
• Reconnect the electrical connectors.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, cutting tool (if needed), torque wrench
• Raise the vehicle and secure it on jack stands.
• Remove any bolts or clamps securing the catalytic converter to the exhaust system.
• If the converter is welded in place, cut it out carefully using a cutting tool.
• Install the new catalytic converter, ensuring proper alignment and sealing.
• Torque all connections to manufacturer specifications.

5. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the PCM.
• Start the engine and allow it to reach operating temperature.