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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery cable to prevent electrical shocks.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, socket set, torque wrench
• Remove the upstream oxygen sensor:
  1. Locate the sensor connected to the exhaust manifold.
  2. Use the O2 sensor socket to unscrew and remove the sensor.
  3. Inspect for any signs of damage or corrosion.
• Install the new upstream oxygen sensor:
  1. Apply anti-seize compound on the threads of the new sensor.
  2. Screw in the new sensor by hand, then tighten it to the manufacturer's torque specification (usually around 30 lb-ft).
• Repeat the process for the downstream oxygen sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, exhaust hangers tool
• Remove the catalytic converter:
  1. Raise the vehicle and secure it with jack stands.
  2. Remove any exhaust clamps or bolts securing the catalytic converter.
  3. Carefully detach the converter from the exhaust pipes and remove it.
• Install the new catalytic converter:
  1. Position the new converter in place.
  2. Reattach the exhaust clamps or bolts, ensuring they are tightened to the specified torque (usually around 40 lb-ft).
  3. Check for proper alignment and secure all hangers.

4. Reset the Check Engine Light

• Reconnect the negative battery cable.
• Use the OBD-II scanner to clear the P0420 code and check for any reoccurrence.