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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors:
   • Find the upstream (pre-catalytic) and downstream (post-catalytic) O2 sensors.
2. Remove the Sensors:
   • Use a socket wrench to unscrew the sensors from the exhaust system.
   • Disconnect the wiring harnesses carefully.
3. Install New Sensors:
   • Apply anti-seize compound to the threads of the new O2 sensors.
   • Screw in the new sensors and tighten them to the manufacturer’s torque specifications (usually around 30 Nm).
   • Reconnect the wiring harnesses.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the Exhaust Components:
   • Use a socket set to unbolt the catalytic converter from the exhaust system.
   • Remove any heat shields if applicable.
2. Inspect the Catalytic Converter:
   • Check for physical damage, blockages, or signs of overheating.
3. Install New Catalytic Converter:
   • Position the new catalytic converter in place and secure it with bolts.
   • Torque to manufacturer specifications (typically around 45-50 Nm).
4. Reattach Heat Shields (if applicable):
   • Reinstall any heat shields that were removed.

4. Clear Codes and Test

1. Reconnect the Battery:
   • Reconnect the battery terminals securely.
2. Clear the Error Codes:
   • Use the OBD-II scanner to clear the P0420 code from the ECU.
3. Test Drive the Vehicle:
   • Drive the vehicle under various conditions to ensure the code does not return.