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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the vehicle battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Remove the upstream (pre-catalytic) oxygen sensor:
  • Use the O2 sensor socket to carefully unscrew the sensor from the exhaust manifold.
  • Disconnect the wiring harness from the sensor.
• Install the new oxygen sensor:
  • Apply anti-seize compound to the threads (if required).
  • Screw in the new sensor and torque to manufacturer specifications (typically around 30-40 lb-ft).
  • Reconnect the wiring harness.
• Repeat the process for the downstream (post-catalytic) oxygen sensor, if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tools (if necessary for exhaust), exhaust sealant.
• Disconnect the exhaust pipes from the catalytic converter:
  • Use a socket set to remove the bolts securing the exhaust pipes.
  • Carefully detach the pipe while ensuring not to damage surrounding components.
• Remove the catalytic converter:
  • Unscrew the bolts or clamps holding the converter in place.
  • If necessary, use cutting tools to remove it if it is welded.
• Install the new catalytic converter:
  • Position the new converter in place and secure it with bolts or clamps.
  • Ensure all connections are tight and use exhaust sealant as needed to prevent leaks.

4. Reset the Engine Control Module (ECM)

• Reconnect the vehicle battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Drive the vehicle for a short while to ensure the code does not return.