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

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Apply penetrating oil to the sensor threads and allow it to sit for a few minutes.
  3. Disconnect the sensor electrical connectors.
  4. Use the O2 sensor socket to remove the sensors.
  5. Install new sensors by threading them in hand-tight, then torque to manufacturer specifications (usually around 30-40 ft-lbs).
  6. Reconnect the electrical connectors.

3. Inspect and Clean/Replace the Catalytic Converter

• Tools Required: Socket set, wrench, catalytic converter cleaner (if cleaning) or replacement unit.
• Sub-steps:
  1. Remove any heat shields covering the catalytic converter if applicable.
  2. Disconnect the exhaust pipes from the catalytic converter using a socket set.
  3. Inspect the catalytic converter for physical damage or excessive carbon buildup.
  4. If cleaning, use a catalytic converter cleaner as per product instructions. If replacement is necessary, install a new catalytic converter, ensuring proper alignment and fit.
  5. Reconnect the exhaust pipes and torque to manufacturer specifications.

4. Clear Error Codes

• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Reconnect the negative battery terminal.