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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the engine is cool and the vehicle is on a flat surface.
• Disconnect the battery to ensure electrical safety.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Locate the sensor on the exhaust manifold or pipe.
  • Use the O2 sensor socket to unscrew it.
• Install the new upstream O2 sensor:
  • Apply anti-seize compound to the threads (if needed).
  • Torque the sensor to the manufacturer’s specifications (typically around 30 ft-lbs).
• Repeat for the downstream (post-catalytic) oxygen sensor if needed.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary).
• Remove the old catalytic converter:
  • Disconnect the exhaust pipes leading to and from the catalytic converter.
  • Use an exhaust pipe cutter if the connections are rusted or difficult to unbolt.
• Install the new catalytic converter:
  • Position it correctly and reconnect the exhaust pipes.
  • Torque all connections to the manufacturer's specifications.
• Reconnect any hangers or brackets that support the exhaust system.

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.