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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the negative battery terminal.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the pre-catalytic converter oxygen sensor by unplugging the connector and using the O2 sensor socket to unscrew it.
• Install the new oxygen sensor and tighten it to manufacturer specifications (typically around 30 ft-lbs).
• Repeat the process for the post-catalytic converter oxygen sensor if required.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack stands, torque wrench
• Raise the vehicle and securely support it with jack stands.
• Disconnect the exhaust piping at both ends of the catalytic converter.
• Remove any mounting bolts or clamps securing the catalytic converter using a socket set.
• Install the new catalytic converter and torque the bolts to manufacturer specifications.
• Reconnect the exhaust piping and ensure all connections are secure.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and let it idle for a few minutes to check for any new codes.