how to fix P0420 code on Ford F-150 14th Generation (2021-2024)

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil
• Locate the upstream and downstream oxygen sensors.
• Apply penetrating oil to the threads of the sensors to ease removal.
• Disconnect the electrical connectors from both oxygen sensors.
• Remove the sensors using the O2 sensor socket; be careful not to damage the wiring.
• Install new oxygen sensors, tightening them to the manufacturer’s specifications (usually around 30 lb-ft).
• Reconnect the electrical connectors.

3. Check and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust pipe cutter, gasket scraper
• Inspect the catalytic converter for any visible damage.
• If replacement is needed, support the vehicle on jack stands.
• Remove the bolts securing the catalytic converter to the exhaust manifold and the muffler using a socket set.
• Cut the exhaust pipe if necessary to remove the old catalytic converter.
• Clean the mating surfaces of the exhaust system with a gasket scraper.
• Install the new catalytic converter, ensuring proper alignment and torque the bolts to the specified value (usually around 30 lb-ft).
• Reconnect any exhaust hangers.

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and let it run for a few minutes to ensure the system is functioning correctly.