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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to avoid any electrical issues.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter
• 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 their respective locations.
  4. Install new oxygen sensors by threading them into place and tightening them to the manufacturer’s specified torque.
  5. Reconnect the electrical connectors to the new sensors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter (if necessary), gaskets, and clamps
• Sub-steps:
  1. Remove the exhaust heat shield if applicable to access the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter using a socket set.
  3. If the catalytic converter is bolted, unbolt it from the exhaust system; if welded, carefully cut it out using an exhaust pipe cutter.
  4. Install the new catalytic converter in place, ensuring proper alignment with exhaust pipes.
  5. Use new gaskets and clamps to secure the connections tightly to prevent leaks.
  6. Reinstall the heat shield.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.