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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use an O2 sensor socket to remove the upstream sensor.
   • Tools Required: O2 sensor socket, wrench.
3. Install the new upstream oxygen sensor and torque it to manufacturer's specifications (typically around 30 ft-lbs).
4. Repeat the process for the downstream oxygen sensor if it was deemed faulty.

3. Inspect and Replace Catalytic Converter

1. Remove the exhaust heat shield if applicable.
2. Unbolt the catalytic converter from the exhaust system using a socket set.
   • Tools Required: Socket set, penetrating oil (if bolts are rusted).
3. Inspect the old catalytic converter for signs of clogging or damage.
4. Install the new catalytic converter and secure it with new gaskets if necessary.
   • Torque Specifications: Follow manufacturer recommendations, typically between 30-40 ft-lbs.
5. Reinstall the heat shield.

4. Clear Codes and Test

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the engine and allow it to reach operating temperature.