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

Solution

1. Preparation

• Gather necessary tools and replacement parts.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Remove the upstream oxygen sensor by using the O2 sensor socket.
• Install the new upstream oxygen sensor and tighten to manufacturer specifications (usually around 30 Nm).
• Repeat the process for the downstream oxygen sensor if it is also suspected to be faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust pipe cutter, gasket scraper, torque wrench.
• Remove the bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe.
• If the converter is welded, use an exhaust pipe cutter to remove it.
• Clean the mating surfaces on the exhaust manifold and exhaust pipe to ensure a proper seal.
• Install the new catalytic converter and secure it with bolts, tightening to manufacturer specifications (usually around 40 Nm).
• Replace any gaskets as needed.

4. Reconnect Battery and Clear Codes

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