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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, multimeter
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the wiring and connectors for any signs of damage or corrosion.
• If the sensors are faulty, replace them with new ones, ensuring they are compatible with the Honda CR-V.
• Reconnect the sensors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool
• Locate the catalytic converter and check for physical damage or significant clogging.
• If replacement is needed, remove the bolts securing the catalytic converter to the exhaust system using a socket set.
• Use an exhaust hanger removal tool to detach any hangers supporting the catalytic converter.
• Install the new catalytic converter, ensuring it is aligned properly, and torque the bolts to the manufacturer's specifications (usually around 25-30 lb-ft).
• Reattach any hangers securely.

4. Clear Error Codes and Test

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