how to fix P0420 code on Ford F-150 12th Generation (2009-2014)

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Using a wrench or socket, carefully remove the oxygen sensors from their respective locations.
3. Inspect the sensors for damage or contamination. If they are faulty, replace with new sensors.
4. Reinstall the new oxygen sensors and torque them to the manufacturer's specifications (usually around 30 ft-lbs).

3. Examine and Replace Catalytic Converter (if necessary)

1. If the catalytic converter is determined to be faulty, locate the mounting points on both the engine and the exhaust system.
2. Unbolt the catalytic converter from the exhaust system using a socket set, taking care to support it as you remove it.
3. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
4. Torque the bolts to the specified values (typically 30-40 ft-lbs).

4. Reset the Engine Control Module (ECM)

1. Reconnect the vehicle battery.
2. Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Start the engine and let it idle for a few minutes.