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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, and extension
• Remove the upstream (pre-catalytic) oxygen sensor using the O2 sensor socket.
• Inspect the sensor for contamination or damage. If faulty, replace it with a new sensor.
• Reinstall the new sensor, ensuring it is securely tightened (typically to the manufacturer's specifications).
• Repeat the process for the downstream (post-catalytic) oxygen sensor if it is suspected to be faulty.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Wrench set, cutting tool (if necessary), gasket scraper
• Remove the exhaust heat shield if applicable to access the catalytic converter.
• Disconnect the exhaust pipes from the catalytic converter using the appropriate wrench.
• Inspect the catalytic converter for any signs of physical damage or blockage.
• If damaged, remove the old catalytic converter and install a new one, ensuring proper alignment.
• Use new gaskets and ensure all bolts are torqued to specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.