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 battery terminal to ensure safety during repairs.

2. Inspect and Clean

• Sub-steps:
  • Remove any debris or soot from around the catalytic converter and exhaust system.
  • Use a cleaning solution designed for catalytic converters if build-up is noted.
  • Reassemble and tighten bolts to factory specifications.

3. Oxygen Sensor Replacement

• Sub-steps:
  • Locate the upstream and downstream oxygen sensors on the exhaust system.
  • Unplug the electrical connectors from each sensor.
  • Use an oxygen sensor socket to remove the old sensors.
  • Install the new oxygen sensors, ensuring to apply anti-seize compound on the threads.
  • Reconnect the electrical connectors securely.

4. Catalytic Converter Replacement (if necessary)

• Sub-steps:
  • Remove any brackets or supports holding the catalytic converter in place.
  • Unbolt the catalytic converter from the exhaust pipes (both upstream and downstream connections).
  • Install the new catalytic converter by reversing the removal steps, ensuring all gaskets are replaced.
  • Torque all bolts to the manufacturer’s specifications.

5. Final Checks

• Sub-steps:
  • Reconnect the negative battery terminal.
  • Start the engine and allow it to reach operating temperature.
  • Monitor for any leaks or unusual noises around the exhaust system.