how to fix P0420 code in Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream and downstream oxygen sensors:
  1. Locate the oxygen sensors on the exhaust system.
  2. Use the O2 sensor socket to unscrew the sensors counter-clockwise.
• Install new oxygen sensors:
  1. Apply anti-seize compound to the threads of the new sensors.
  2. Screw in the new sensors by hand and then tighten to the manufacturer's specified torque.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Remove the catalytic converter:
  1. Disconnect the exhaust pipes from the catalytic converter using a socket set.
  2. If necessary, cut the exhaust pipes using an exhaust pipe cutter.
• Install the new catalytic converter:
  1. Position the new catalytic converter in place and secure it with new gaskets.
  2. Tighten all bolts to the specified torque settings.

4. Reconnect Battery and Clear Codes

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