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

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Instructions:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Use the O2 sensor socket to carefully unscrew the sensors.
  3. Inspect the old sensors for signs of damage or corrosion.
  4. Install new oxygen sensors, tightening them to the manufacturer's specifications (usually around 30 ft-lbs).

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

• Tools Required: Socket set, exhaust pipe cutter, gasket scraper.
• Instructions:
  1. Remove the exhaust pipes connected to the catalytic converter using a socket set.
  2. Carefully detach the catalytic converter from the exhaust system.
  3. Inspect the mounting flanges and gaskets; replace if damaged.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reattach the exhaust pipes and tighten all bolts to the specified torque.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the codes and reset the check engine light.