how to fix Honda Pilot YF4 (2023-Present) P0420 code for catalytic converter

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent any electrical issues.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) O2 sensors in the exhaust system.
  2. Disconnect the electrical connectors from both O2 sensors.
  3. Use the O2 sensor socket to remove the sensors from their respective locations.
  4. Install the new O2 sensors and torque them to the manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter, new gaskets, torque wrench.
• Sub-steps:
  1. Inspect the catalytic converter for physical damage or clogging.
  2. If damage is found, use an exhaust pipe cutter to remove the defective catalytic converter from the exhaust system.
  3. Clean the exhaust flanges and remove any old gasket material.
  4. Install the new catalytic converter with new gaskets, ensuring proper alignment.
  5. Torque the mounting bolts to the manufacturer's specifications (check service manual for exact values).

4. Reset the Check Engine Light

• Use the OBD-II scanner to clear the P0420 code.
• Reconnect the negative battery terminal.