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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shocks.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Multimeter
• Exhaust leak detector (optional)

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use a socket to remove the sensors from their respective locations.
  4. Install the new oxygen sensors by screwing them in place and tightening them to the manufacturer's specifications (typically 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Check and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. If the oxygen sensors are functioning correctly and the code persists, inspect the catalytic converter for damage or clogging.
  2. Remove the bolts connecting the catalytic converter to the exhaust manifold and the exhaust pipe using a socket set.
  3. Carefully remove the old catalytic converter. If it's welded, you may need a cutting tool to remove it.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust system. Use new gaskets as needed.
  5. Torque the bolts to the manufacturer's specifications (usually around 30-45 lb-ft, depending on the model).

4. Reconnect Battery

• Reconnect the negative battery terminal and ensure all connections are secure.