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

Solution

1. Preparation

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

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Multimeter

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Unplug the electrical connectors from both sensors.
  3. Use a socket wrench to remove the oxygen sensors from the exhaust system.
  4. Install the new oxygen sensors, ensuring they are properly torqued according to manufacturer specifications (usually around 30-40 lb-ft).
  5. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Inspect the catalytic converter for any physical damage or clogs.
  2. If replacement is necessary, detach the catalytic converter from the exhaust system using a socket set.
  3. Install the new catalytic converter, ensuring all gaskets and seals are replaced to prevent leaks.
  4. Torque the bolts to manufacturer specifications (typically around 25-30 lb-ft).

4. Clear Codes and Test Drive

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0420 code from the ECM.
  2. Reconnect the battery if it was disconnected.
  3. Start the vehicle and allow it to reach operating temperature.
  4. Conduct a test drive to ensure the vehicle operates without any issues and check for recurring codes.