how to fix P0420 code on Honda Pilot Third Generation (2016-present)

Solution

1. Preparation

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

2. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream oxygen sensor:
  1. Locate the upstream (pre-catalytic converter) O2 sensor.
  2. Use the O2 sensor socket to remove the sensor from the exhaust manifold.
  3. Install the new upstream O2 sensor, torque to manufacturer specifications (usually around 30 lb-ft).
• Remove the downstream oxygen sensor:
  1. Locate the downstream (post-catalytic converter) O2 sensor.
  2. Use the O2 sensor socket to remove the sensor.
  3. Install the new downstream O2 sensor, torque to specifications.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands
• Raise the vehicle securely using jack stands.
• Remove the catalytic converter:
  1. Unbolt the exhaust pipes connected to the catalytic converter.
  2. Remove any brackets or hangers holding the catalytic converter in place.
  3. Carefully take out the catalytic converter.
• Install the new catalytic converter:
  1. Position the new catalytic converter in place.
  2. Reattach the exhaust pipes and tighten bolts to manufacturer specifications.
  3. Reinstall any brackets or hangers.

4. Clear Codes and Recheck

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code and any other related codes.
• Start the vehicle and allow it to reach operating temperature.