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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on electrical systems.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Using a socket wrench, unbolt and remove the upstream oxygen sensor.
3. Install the new upstream oxygen sensor and torque it to the manufacturer's specifications (usually around 30 Nm).
4. Repeat the process for the downstream oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter

1. If the oxygen sensors are functioning correctly, locate the catalytic converter.
2. Unbolt the exhaust pipes connected to the catalytic converter using a socket set (usually 14 or 17 mm bolts).
3. Remove the catalytic converter from its mounting brackets.
4. Install the new catalytic converter, ensuring it is aligned properly with the exhaust system.
5. Torque the bolts to the manufacturer's specifications.

4. Reconnect Battery and Clear Codes

1. Reconnect the battery terminals securely.
2. Use the OBD-II scanner to clear the P0420 error code from the vehicle's computer.