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

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the battery to prevent electrical shorts.
• Ensure the vehicle is on a flat surface and secure it with jack stands if elevated.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the electrical connectors from the sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust system.
  4. Install the new sensors and torque them to the manufacturer’s specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tools (if necessary), torque wrench.
• Sub-steps:
  1. Inspect the catalytic converter for signs of damage or blockage.
  2. If replacement is needed, disconnect the exhaust pipe from the catalytic converter.
  3. Remove any mounting bolts or brackets securing the converter.
  4. Install the new catalytic converter, ensuring all gaskets are replaced.
  5. Torque the mounting bolts to the manufacturer's specifications.

4. Reset Engine Control Module (ECM)

• Tools Required: OBD-II scanner.
• 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 allow it to reach operating temperature.