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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, jack stands, safety goggles.
• Ensure the vehicle is parked on a level surface and the engine is cool. Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Remove the sensors using a socket wrench.
  4. Install new oxygen sensors, ensuring they are torqued to the manufacturer's specifications (usually around 30 ft-lbs).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Unbolt the catalytic converter from the exhaust pipes using a socket set.
  4. Inspect the catalytic converter for signs of damage or blockage.
  5. If damaged, replace with a new catalytic converter, ensuring proper alignment.
  6. Torque the bolts to the manufacturer's specifications.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Start the engine and allow it to reach operating temperature.
  4. Conduct a test drive to ensure the check engine light does not reappear and the vehicle operates smoothly.