how to fix P0420 code on Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Remove the downstream oxygen sensor (post-catalytic converter):
  1. Locate the downstream oxygen sensor.
  2. Use the O2 sensor socket to carefully unscrew it from its position.
• Install the new downstream oxygen sensor:
  1. Apply anti-seize compound to the threads of the new sensor (if recommended).
  2. Torque to manufacturer's specifications (usually around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket
• Remove the catalytic converter:
  1. Disconnect any heat shields or brackets securing the converter.
  2. Use the socket set to remove the bolts securing the catalytic converter to the exhaust system.
  3. Carefully remove the converter and inspect it for physical damage.
• Install the new catalytic converter:
  1. Position the new converter in place.
  2. Secure it with new gaskets and bolts, torqued to manufacturer's specifications (usually around 30-40 ft-lbs).

4. Reconnect Battery and Clear Codes

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