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

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the sensors for damage or contamination.
• If faulty, replace the oxygen sensors with new, manufacturer-recommended sensors.
• Reinstall the sensors and torque them to the manufacturer’s specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tool (if necessary)
• Inspect the catalytic converter for physical damage.
• If damaged, detach the catalytic converter from the exhaust system using a socket set.
• If the converter is welded in, use a cutting tool to remove it carefully.
• Install the new catalytic converter, ensuring proper alignment.
• Torque all bolts to the manufacturer’s specifications (typically around 40 lb-ft).

4. Clear Codes and Test

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