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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  • Disconnect the electrical connector.
• Install the new upstream oxygen sensor:
  • Apply anti-seize compound to the threads of the new sensor.
  • Screw it into place and tighten to manufacturer specifications (typically around 30 lb-ft).
  • Reconnect the electrical connector.
• Repeat the process for the downstream (post-catalytic) oxygen sensor.

3. Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust clamps
• Remove the faulty catalytic converter:
  • Disconnect the exhaust pipes from the catalytic converter and use a socket set to unbolt it from the exhaust manifold and exhaust pipe.
• Install the new catalytic converter:
  • Position the new converter in place and bolt it to the exhaust manifold and downstream exhaust pipe.
  • Tighten all bolts to the specified torque.
  • Reconnect any exhaust hangers or clamps as necessary.

4. Clear Error Codes and Test

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the engine control module.
• Start the engine and let it reach operating temperature.