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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the battery to ensure safety while working on the vehicle.
• Allow the engine to cool before beginning work on the exhaust system.

2. Inspect and Repair Exhaust Leaks

• Tools Required: Socket set, exhaust sealant
  • Use a socket set to remove any components obstructing access to the exhaust system.
  • Inspect the entire exhaust system for leaks or damaged sections.
  • Use exhaust sealant to repair small leaks or replace damaged sections as necessary.

3. Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
  • Locate the upstream and downstream oxygen sensors.
  • Use an O2 sensor socket to remove the faulty sensors.
  • Install the new sensors, ensuring they are torqued to the manufacturer's specifications (typically around 30 Nm or 22 lb-ft).
  • Reconnect the wiring harness to the sensors.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust clamp, torch (if rusted)
  • Remove the exhaust components leading to the catalytic converter using a socket set.
  • If the catalytic converter is rusted and stuck, carefully use a torch to heat the area around the bolts to loosen them.
  • Install the new catalytic converter in place, using new exhaust gaskets and clamps as necessary.
  • Reassemble any exhaust components that were removed.

5. Clear Codes and Test

• Reconnect the battery and use an OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Perform a test drive to ensure the check engine light does not reappear.