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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on the vehicle.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Sub-steps:
  1. Remove the O2 sensor wiring harness.
  2. Using the O2 sensor socket, carefully unscrew the upstream and downstream oxygen sensors from their respective locations.
  3. Test the new sensors with a multimeter before installation (resistance and voltage tests).
  4. Install the new sensors in their respective locations and reconnect the wiring harness.

3. Check and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if required).
• Sub-steps:
  1. Disconnect the exhaust system from the catalytic converter, ensuring all fasteners are removed.
  2. If needed, cut the exhaust pipe to remove the old catalytic converter.
  3. Install the new catalytic converter, ensuring it is fitted correctly.
  4. Tighten all bolts and clamps to the manufacturer's specified torque values.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Start the engine and perform a test drive under various conditions to ensure the issue is resolved.