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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Allow the engine to cool down.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Find 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 both sensors from their respective locations.

3. Inspect the Sensors:

   • Check the sensors for any signs of damage or excessive carbon buildup.

4. Replace if Necessary:

   • If damaged, install new oxygen sensors by reversing the removal process. Ensure they are tightened to manufacturer specifications (generally around 30 lb-ft).

3. Inspect Catalytic Converter

1. Visual Inspection:

   • Inspect for any signs of physical damage or excessive rust on the catalytic converter.

2. Check for Clogs:

   • Perform a backpressure test using a pressure gauge inserted into the O2 sensor port. A backpressure above 2.5 psi at idle indicates a clogged converter.

3. Replace Catalytic Converter:

   • If clogged or damaged, remove the catalytic converter by unbolting it from the exhaust system and replacing it with a new unit. Ensure proper alignment and secure with new gaskets.

4. Clear Codes and Test

1. Reconnect Battery:

   • Reattach the battery terminals and ensure a secure connection.

2. Clear Error Codes:

   • Use the OBD-II scanner to clear the P0420 code and any other stored codes.

3. Test Drive:

   • Take the vehicle for a test drive to allow the ECU to monitor the system and recheck for any error codes.