how to fix P0420 code on Ford F-150 13th Generation (2015-2020)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down completely before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

1. Remove Oxygen Sensors:

   • Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
   • Use an O2 sensor socket or wrench to carefully unscrew and remove the sensors.

2. Install New Oxygen Sensors:

   • Apply anti-seize compound to the threads of the new sensors.
   • Install the new upstream and downstream oxygen sensors, tightening to the specified torque (typically around 30 lb-ft).

3. Replace Catalytic Converter (if necessary)

1. Remove the Old Catalytic Converter:

   • Use a socket set to remove the bolts securing the catalytic converter to the exhaust system.
   • Carefully detach the converter from the exhaust pipes, ensuring there are no residual gaskets or debris left behind.

2. Install New Catalytic Converter:

   • Position the new catalytic converter into place and align it with the exhaust pipes.
   • Secure the converter with new gaskets and bolts, torquing them to the manufacturer's specifications (usually around 40 lb-ft).

4. Clear Codes and Test

1. Reconnect Battery:

   • Reconnect the negative battery terminal.

2. Clear the Diagnostic Codes:

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

3. Test Drive the Vehicle:

   • Drive the vehicle under various conditions to ensure the check engine light does not reappear and that the vehicle operates smoothly.