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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Ensure the vehicle is on a flat surface and secure it with wheel chocks.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Use an O2 sensor socket to carefully remove both oxygen sensors.
  3. Inspect the sensors for damage or contamination.
  4. If faulty, install new sensors; torque to manufacturer specifications (usually around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove any heat shields or brackets securing the catalytic converter.
  2. Use a socket set to unbolt the catalytic converter from the exhaust system.
  3. Inspect the old catalytic converter for blockages or damage (e.g., rattling noise).
  4. Install the new catalytic converter, ensuring proper alignment and torque to specifications (typically around 30 ft-lbs).
  5. Reinstall heat shields and brackets.

4. Clear Codes and Test

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code.
  3. Take the vehicle for a test drive to allow the ECU to recheck the catalytic system.