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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shock.
• Allow the vehicle to cool down before starting work on the exhaust system.

2. Inspect and Repair Exhaust Leaks

• Tools Required: Socket set, exhaust gasket, exhaust sealant.
• Inspect the entire exhaust system for leaks using a visual check and by listening for hissing sounds.
• If any leaks are found, use a socket set to remove damaged sections and replace them with new gaskets or sealant.

3. Test and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, multimeter.
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Test the sensors’ resistance and voltage output with a multimeter; replace if they do not meet specifications.
• Install the new sensors following proper torque specifications (usually around 30 ft-lbs).

4. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Wrench set, cutting tool (if welding is necessary), replacement catalytic converter.
• Visually inspect the catalytic converter for damage or clogging. If necessary, remove it by unbolting or cutting exhaust pipes as needed.
• Install the new catalytic converter ensuring all connections are secure and properly torqued (usually around 40-50 ft-lbs).

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code and reset the system.