how to fix P0420 code in Honda CR-V Sixth Generation (2023-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety while working on electrical components.
• Allow the vehicle to cool down if the engine has been running.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove Sensors:
   • Use a wrench to carefully unscrew the oxygen sensors from their locations.
   • Disconnect the wiring harness from both sensors.
3. Install New Sensors:
   • Apply anti-seize compound on the threads of the new sensors.
   • Install the upstream sensor first, followed by the downstream sensor, ensuring they are tightened to the manufacturer’s specifications (typically around 30 lb-ft).
   • Reconnect the wiring harness to each sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components:
   • Support the exhaust system with a jack stand.
   • Remove any bolts or clamps securing the catalytic converter to the exhaust system.
2. Inspect for Damage:
   • Check for physical damage or blockage in the catalytic converter.
3. Install New Catalytic Converter:
   • Position the new catalytic converter in place and secure it with bolts or clamps, tightening to the specified torque.
   • Ensure all connections are sealed properly to prevent leaks.

4. Reset the ECU

1. Reconnect the Battery: Reconnect the vehicle battery after all repairs are complete.
2. Clear Error Codes: Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Test Drive: Start the vehicle and perform a test drive to allow the ECM to recalibrate.