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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust pipes.
  4. Install the new oxygen sensors, tightening them to the manufacturer’s specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tool (if needed), gaskets
• Sub-steps:
  1. Locate the catalytic converter in the exhaust system.
  2. Remove the bolts securing the catalytic converter to the exhaust pipes using a socket set.
  3. If necessary, cut the exhaust pipes using a cutting tool to remove the old catalytic converter.
  4. Install the new catalytic converter with new gaskets and secure it with the bolts, tightening to the manufacturer's torque specifications (usually around 25 lb-ft).
  5. Ensure all connections are leak-free.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear any stored codes from the computer.