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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid any electrical issues.
• Allow the exhaust system to cool down before working on it.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream O2 sensor (before the catalytic converter) and inspect for damage or contamination.
• If faulty, install the new O2 sensor and torque it to the manufacturer’s specification (typically around 30 lb-ft).
• Repeat the process for the downstream O2 sensor (after the catalytic converter).

3. Inspect and Repair Exhaust Leaks

• Visually inspect the exhaust system for cracks, holes, or loose connections.
• If any leaks are detected, repair or replace the affected section of the exhaust using appropriate exhaust repair materials or replace the component entirely.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, wrench set, jack stands, and a new catalytic converter.
• Raise the vehicle and secure it with jack stands.
• Remove the bolts securing the catalytic converter to the exhaust system and any heat shields.
• Carefully detach the old catalytic converter and install the new one, ensuring proper alignment.
• Torque the bolts to the manufacturer's specification (reference the service manual for exact values).

5. Reconnect Battery and Reset ECU

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Start the engine and allow it to reach normal operating temperature.