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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Raise and support the vehicle securely on jack stands.

2. Inspect and Test Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter.
• Sub-steps:
  1. Remove the connectors from the upstream and downstream oxygen sensors.
  2. Use the multimeter to test the voltage output of the sensors while the engine is running.
  3. If the upstream sensor is faulty (not fluctuating between 0.1V and 0.9V), replace it.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed), penetrating oil.
• Sub-steps:
  1. Check the catalytic converter for any physical damage or blockage.
  2. If damaged, remove the exhaust pipes connected to the catalytic converter using a socket set.
  3. If necessary, use an exhaust pipe cutter to separate the damaged catalytic converter.
  4. Install the new catalytic converter, ensuring to align it properly with the exhaust system.
  5. Torque the bolts to the manufacturer’s specifications.

4. Clear Codes and Reconnect Battery

• Sub-steps:
  1. Reconnect the battery terminals.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  3. Start the engine and allow it to reach operating temperature.