how to fix P0420 code on Ford F-150 Fourteenth Generation (2021-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent any electrical issues.

2. Inspect Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter.
• Check the upstream oxygen sensor (before the catalytic converter) for proper voltage output (0.1-0.9 volts).
• Check the downstream oxygen sensor (after the catalytic converter) for stable voltage (should fluctuate less than the upstream sensor).
• If either sensor is faulty, replace the sensor as needed.

3. Inspect and Repair Exhaust System

• Tools Required: Socket set, exhaust pipe cutter (if needed), jack stands.
• Check all exhaust connections and pipes for leaks or damage.
• Repair or replace any damaged sections of the exhaust system.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, gasket scraper.
• Remove the bolts securing the catalytic converter to the exhaust system.
• Carefully detach the catalytic converter and replace it with a new catalytic converter.
• Ensure to use a new gasket and torque the bolts to the manufacturer's specifications (usually around 30-40 lb-ft).

5. Reset the OBD-II System

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