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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil
• If oxygen sensors are faulty, replace them.
  1. Locate the upstream and downstream oxygen sensors.
  2. Apply penetrating oil to the sensor threads if they are rusted.
  3. Use an O2 sensor socket to remove the faulty sensor.
  4. Install the new sensor and torque to manufacturer specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter or saw, gasket scraper
• If the catalytic converter is determined to be inefficient:
  1. Remove the exhaust system components connected to the catalytic converter.
  2. Cut or unbolt the old catalytic converter from the exhaust pipe.
  3. Clean the mating surfaces with a gasket scraper.
  4. Install the new catalytic converter and torque bolts to manufacturer specifications.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• After repairs:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Test drive the vehicle for at least 20 minutes to ensure the code does not reappear.