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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove the Sensors: Use an oxygen sensor socket to remove the upstream and downstream sensors.
3. Check the Sensors: Inspect the sensors for signs of wear or contamination. If they are faulty, replace with new sensors.
4. Install New Sensors: Thread the new oxygen sensors into place and tighten to manufacturer specifications (typically around 30-40 Nm).
5. Reconnect Electrical Connectors: Ensure all connectors are securely fastened.

3. Inspect and Replace the Catalytic Converter

1. Remove Exhaust Components: If the catalytic converter is damaged, unbolt the exhaust components leading to it using a socket set.
2. Inspect the Catalytic Converter: Check for any signs of physical damage, such as dents or a rattling sound which indicates internal failure.
3. Install New Catalytic Converter: Position the new catalytic converter and secure it with bolts, torquing to manufacturer specifications (typically around 25-30 Nm).
4. Reattach Exhaust Components: Reassemble any removed exhaust parts, ensuring all gaskets are replaced to prevent leaks.

4. Final Steps

1. Reconnect the Battery: Reattach the negative battery terminal.
2. Clear Error Codes: Use the OBD-II scanner to clear the P0420 code.
3. Test Drive the Vehicle: Drive the vehicle under varied conditions for at least 20-30 minutes to monitor performance.