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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the exhaust system to cool before starting the repair.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Remove the negative battery terminal.
• Locate and remove the pre-catalytic and post-catalytic oxygen sensors using the O2 sensor socket.
• Inspect the connectors for corrosion or damage; clean or replace as necessary.
• Install new oxygen sensors (torque to manufacturer specifications, typically around 30 lb-ft).

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

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Remove any heat shields if applicable.
• Unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
• Inspect the old catalytic converter for damage or blockage; replace if necessary.
• Install the new catalytic converter, ensuring proper alignment and sealing.
• Torque all bolts to manufacturer specifications (consult repair manual for exact values).

4. Clear Codes and Test

• Reconnect the battery and use an OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Drive the vehicle under various conditions to ensure the check engine light does not reappear and the system operates correctly.