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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Gather the vehicle's repair manual for specific torque specifications.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.

2. Remove the Oxygen Sensors:

   • Use an oxygen sensor socket to carefully unscrew the sensors from their locations.
   • Be cautious of exhaust heat; use gloves if necessary.

3. Install New Oxygen Sensors:

   • Apply anti-seize compound to the threads of the new sensors if recommended.
   • Screw in the new sensors by hand, then tighten to the manufacturer's specifications (usually around 30 lb-ft).
   • Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Check the Catalytic Converter:

   • If the oxygen sensor replacement does not resolve the code, inspect the catalytic converter for damage or clogging.

2. Remove the Catalytic Converter:

   • Loosen the exhaust clamps and remove the bolts securing the catalytic converter.
   • Carefully remove it from the exhaust system.

3. Install New Catalytic Converter:

   • Position the new catalytic converter in place and secure it with bolts to the exhaust system.
   • Ensure all clamps are tight and there are no exhaust leaks.

4. Clear Codes and Test

1. Reconnect the Battery:

   • Reconnect the battery terminals.

2. Clear the Codes:

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

3. Test Drive:

   • Take the vehicle for a test drive to ensure the check engine light does not reappear and monitor for any symptoms.