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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, safety glasses, gloves.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Test O2 Sensors

• Remove the upstream and downstream oxygen sensors using a socket wrench.
• Use a multimeter to test the voltage output of the upstream O2 sensor; it should oscillate between 0.1V and 0.9V.
• Test the downstream O2 sensor; it should show a stable voltage (around 0.5V).
• If either sensor is faulty, replace it.

3. Inspect Catalytic Converter

• Visually inspect the catalytic converter for any signs of damage or clogging.
• If the converter is damaged or performance is below specifications, it must be replaced.
• Replacement Procedure:
  • Unbolt the catalytic converter from the exhaust system using a socket set.
  • Install the new catalytic converter, ensuring proper alignment.
  • Torque the bolts to the manufacturer's specifications (typically around 30-40 ft-lbs).

4. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's memory.
• Take the vehicle for a test drive to monitor performance and ensure the check engine light does not re-illuminate.