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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Remove the oxygen sensor(s) located before and after the catalytic converter using an oxygen sensor socket.
2. Inspect the wiring and connectors for any signs of damage or corrosion.
3. Install new oxygen sensors (if faulty) and torque them to manufacturer specifications (typically around 30 lb-ft).
4. Reconnect the battery terminal.

3. Inspect and Replace Catalytic Converter

1. Identify the catalytic converter location and secure the vehicle on jack stands.
2. Remove the exhaust clamps or bolts securing the catalytic converter using a socket set.
3. Carefully detach the catalytic converter from the exhaust system.
4. Inspect the old converter for signs of damage or blockage.
5. Install the new catalytic converter, ensuring proper alignment and secure it with clamps or bolts; torque to specifications (usually around 20 lb-ft).
6. Reconnect any sensors or components that were removed.

4. Clear Error Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
3. Perform a test drive to ensure the check engine light does not reappear.