how to fix P0420 code on my Genesis G70 IG (2017-2023)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is on a level surface and secure it using wheel chocks.
• Disconnect the battery to ensure safety during electrical work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Use a socket wrench to carefully remove both sensors.
3. Inspect the sensors for signs of wear or contamination; replace if necessary.
4. Apply anti-seize compound to the threads of the new sensors and install them, tightening them to the manufacturer’s specifications (usually around 30 lb-ft).
5. Reconnect the battery after installation.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. If the catalytic converter is determined to be faulty, first, disconnect any oxygen sensors attached to it.
2. Unbolt the catalytic converter from the exhaust system using a socket set (torque specifications may vary; consult service manual).
3. Remove the old catalytic converter and inspect the gaskets; replace if damaged.
4. Install the new catalytic converter, ensuring proper alignment with the exhaust system.
5. Torque the bolts to the manufacturer's specification (typically around 30 lb-ft).
6. Reconnect any oxygen sensors that were previously removed.

4. Final Check

1. Start the engine and let it idle for a few minutes.
2. Check for any exhaust leaks around the catalytic converter and sensor connections.
3. Clear any error codes using the OBD-II scanner.