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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.
• Gather necessary tools and parts.

2. Inspect and Repair Exhaust System

• Tools Required: Socket set, torque wrench, exhaust leak detection fluid.
• Inspect the exhaust system for leaks or damage. Use exhaust leak detection fluid to locate small leaks.
• If a leak is found, repair or replace the damaged section of the exhaust pipe.

3. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Locate the upstream and downstream oxygen sensors.
• Disconnect the electrical connectors from both sensors.
• Use the O2 sensor socket to remove the sensors from the exhaust system.
• Install the new sensors, tightening them to the manufacturer's specifications (typically around 30-40 lb-ft).
• Reconnect the electrical connectors.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, cutting torch (if necessary).
• Disconnect the exhaust pipes connected to the catalytic converter.
• Remove any heat shields or brackets securing the converter.
• If the converter is bolted, remove the bolts; if welded, cut the converter out carefully.
• Install the new catalytic converter, ensuring proper alignment and sealing.
• Reattach any heat shields or brackets and tighten all connections to the specified torque.

5. Reconnect Battery and Clear Codes

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