how to diagnose Honda CR-V Fifth Generation (2017-2022) with code P0420

Solution

1. Preparation

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

2. Inspect Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter
• Remove the upstream and downstream oxygen sensors using a socket wrench.
• Test the resistance of the sensors; compare values with manufacturer specifications.
• If the oxygen sensors are faulty, replace them with new ones.

3. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed), gaskets
• Remove the exhaust system components (if necessary) to access the catalytic converter.
• Unbolt and remove the old catalytic converter from the exhaust system.
• Install the new catalytic converter, ensuring to use new gaskets and torque the bolts to manufacturer specifications.
• Reassemble any components removed during the process.

4. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and perform a test drive to ensure the issue is resolved.