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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  • Remove the oxygen sensors using an O2 sensor socket.
  • Inspect the sensors for any signs of damage or contamination.
  • If faulty, replace with new OEM or high-quality aftermarket oxygen sensors.
  • Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  • Visually inspect the catalytic converter for damage or signs of overheating.
  • If replacement is necessary, unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  • Remove any heat shields if applicable.
  • Install the new catalytic converter, ensuring proper alignment.
  • Torque the bolts to factory specifications (usually around 30-40 lb-ft, refer to service manual for exact specifications).
  • Reinstall any heat shields that were removed.

4. Clear Codes and Test Drive

• Sub-steps:
  • Reconnect the vehicle battery.
  • Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
  • Start the engine and conduct a test drive to ensure normal operation and to check for the reappearance of the check engine light.