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

Solution

1. Preparation

• Gather tools and parts required for repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to ensure safety.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors (typically found before and after the catalytic converter).
  2. Use the O2 sensor socket to remove the upstream sensor first.
  3. Inspect the sensor for contamination; replace if faulty.
  4. Repeat the removal process for the downstream sensor.
  5. Install new sensors, ensuring to torque them to manufacturer specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter (if necessary), torque wrench.
• Sub-steps:
  1. Inspect the catalytic converter for any damage, rattling, or blockage.
  2. If replacement is necessary, use a socket set to remove the bolts securing the catalytic converter to the exhaust system.
  3. Remove the old catalytic converter; cut the exhaust pipes if necessary using the exhaust pipe cutter.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Torque the bolts to the manufacturer specifications (usually around 30-40 lb-ft).

4. Finalize Installation

• Sub-steps:
  1. Reconnect the battery.
  2. Start the engine and let it idle for a few minutes.
  3. Check for any exhaust leaks around the newly installed components.