how to diagnose P0420 code in my Genesis G70 IG (2017-2023)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety during repairs.

2. Oxygen Sensor Inspection

• Tools Required: OBD-II scanner, multimeter
• Remove the pre-catalytic and post-catalytic oxygen sensors using an oxygen sensor socket.
• Test the sensors with a multimeter to ensure they are functioning correctly (refer to manufacturer specifications for resistances).
• If faulty, replace the sensors with OEM or quality aftermarket parts.

3. Catalytic Converter Inspection

• Tools Required: Wrench set, exhaust pipe cutter (if necessary)
• Inspect the catalytic converter for physical damage or blockage.
• If the converter shows signs of damage or clogging, proceed to replace it.
• Use a wrench to disconnect the exhaust pipes from the catalytic converter, and remove any mounting bolts.
• Carefully extract the old catalytic converter and replace it with a new one.

4. Reinstallation and Connection

• Reinstall the oxygen sensors into the new catalytic converter, ensuring proper torque specifications (typically around 30 lb-ft).
• Reconnect any exhaust pipes and secure all connections with the proper hardware.
• Reconnect the vehicle battery.