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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface with the engine off and cooled down.
• Disconnect the battery to prevent any electrical issues during the repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench, multimeter.
• Remove the upstream (pre-catalytic converter) oxygen sensor:
  1. Locate the upstream O2 sensor, usually near the engine.
  2. Unplug the electrical connector.
  3. Use the O2 sensor socket to unscrew and remove the sensor.
• Install the new upstream O2 sensor:
  1. Apply anti-seize compound on the threads (if applicable).
  2. Torque to manufacturer specification (typically around 30 lb-ft or as specified).
  3. Reconnect the electrical connector.
• Repeat the process for the downstream (post-catalytic converter) oxygen sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter, new exhaust gaskets.
• Raise the vehicle securely on jack stands and locate the catalytic converter.
• Remove the bolts securing the catalytic converter to the exhaust system:
  1. Use a socket set to remove bolts from both ends of the catalytic converter.
  2. Cut any exhaust clamps if necessary.
• Remove the old catalytic converter and replace it with the new one:
  1. Position the new catalytic converter in place.
  2. Secure it with bolts and torque to the manufacturer's specifications.
  3. Replace any gaskets to prevent leaks.
• Lower the vehicle and reconnect the battery.