how to fix P0420 code on Honda CR-V Fifth Generation (2017-2022)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Allow the exhaust system to cool before working on it.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use the O2 sensor socket to carefully remove the upstream sensor.
  3. Inspect the sensor for signs of wear or damage; replace if necessary.
  4. Install the new sensor and torque to the manufacturer's specification (typically around 30-50 ft-lbs).
  5. Repeat the process for the downstream oxygen sensor if it is faulty.

3. Test and Replace Catalytic Converter (if necessary)

• Tools Required: Jack and jack stands, socket set, exhaust gasket
• Sub-steps:
  1. Raise the vehicle securely and support it with jack stands.
  2. Inspect the catalytic converter for any physical damage or blockage.
  3. If damaged, unbolt the catalytic converter from the exhaust system.
  4. Remove any exhaust gaskets and clean mating surfaces.
  5. Install the new catalytic converter, ensuring proper alignment and sealing with new gaskets.
  6. Torque all bolts to the manufacturer’s specification.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Take the vehicle for a test drive to ensure normal operation and to check if the check engine light returns.