how to fix P0420 code in Honda CR-V Sixth Generation (2023-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream O2 sensor (before the catalytic converter) by:
  1. Locating the O2 sensor wiring harness and disconnecting it.
  2. Using the O2 sensor socket to loosen and remove the sensor.
  3. Installing the new O2 sensor and torque to the manufacturer’s specifications (typically around 30 lb-ft).
  4. Reconnect the wiring harness.
• Repeat this for the downstream O2 sensor (after the catalytic converter) if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed)
• Check the catalytic converter for any physical damage. If replacement is needed:
  1. Remove the exhaust pipes connected to the catalytic converter using the socket set.
  2. If required, cut the exhaust pipe with the exhaust pipe cutter to remove the old catalytic converter.
  3. Install the new catalytic converter and ensure all bolts are tightened to the specified torque (typically around 30 lb-ft).
  4. Reattach the exhaust pipes securely.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the system.
• Start the engine and allow it to run for a few minutes, then take the vehicle for a test drive to ensure the code does not return.