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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  • Remove the upstream oxygen sensor using a socket wrench; be cautious of the wiring.
  • Use a multimeter to test the resistance of the oxygen sensor; replace if it's out of specification.
  • Install the new oxygen sensor and reconnect the wiring.

3. Check and Replace the Catalytic Converter

• Sub-steps:
  • Remove the exhaust pipes connected to the catalytic converter using a socket set.
  • Check for any visible damage to the catalytic converter (e.g., dents or cracks).
  • If necessary, remove the catalytic converter from the exhaust system.
  • Install the new catalytic converter, ensuring proper alignment with exhaust hangers and gaskets.
  • Reconnect the exhaust pipes and torque bolts to the manufacturer's specifications (typically around 40-50 lb-ft).

4. Clear the Codes and Test

• Sub-steps:
  • Reconnect the negative battery terminal.
  • Use the OBD-II scanner to clear the P0420 code from the ECM.
  • Start the vehicle and allow it to reach operating temperature.
  • Perform a test drive to monitor for the return of the P0420 code.

Tools Required:

• OBD-II scanner
• Socket set
• Multimeter
• Oxygen sensor socket
• Torque wrench

Parts Required:

• Upstream oxygen sensor (if faulty)
• Downstream oxygen sensor (if faulty)
• Catalytic converter (if necessary)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Allow the exhaust system to cool down before working on it to avoid burns.
• Wear safety glasses and gloves while working on the exhaust system.