how to fix the P0420 error code in Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety during repairs.
• Raise the vehicle securely on jack stands.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  • Disconnect the electrical connectors from both sensors.
  • Use a socket wrench to remove the sensors from their respective locations.
  • Install new oxygen sensors by reversing the removal process. Torque the sensors to manufacturer specifications (typically around 30 lb-ft).
  • Reconnect the electrical connectors to the sensors.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  • Inspect the catalytic converter for physical damage or blockage.
  • If replacement is necessary, unbolt the catalytic converter from the exhaust system using a socket set.
  • Remove any gaskets or seals that may need replacement.
  • Install the new catalytic converter, ensuring proper alignment with the exhaust system.
  • Use new gaskets and torque the bolts to the specified torque value (usually around 25 lb-ft).

4. Clear Error Codes

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