how do I fix the P0420 code on my Genesis G70 IG (2017-2023)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery.

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 O2 sensor socket to carefully unscrew the sensors from their respective locations.

3. Install New Sensors:

   • Apply anti-seize compound to the threads of the new sensors.
   • Screw them into place and tighten to the manufacturer’s torque specifications (typically around 30-40 lb-ft, but verify with service manual).

3. Inspect and Clean/Replaced Catalytic Converter

1. Remove the Catalytic Converter:

   • Disconnect any exhaust hangers and bolts securing the catalytic converter.
   • Carefully remove the catalytic converter from the exhaust system.

2. Inspect for Damage:

   • Check for signs of clogging or physical damage (e.g., dents, cracks).
   • If damaged, replace the catalytic converter with a new OEM or high-quality aftermarket unit.

3. Install New or Cleaned Catalytic Converter:

   • If cleaning is an option, use a specialized catalytic converter cleaner, following the manufacturer’s instructions.
   • Reinstall the catalytic converter, ensuring all connections are tight and secure.

4. Reset the Engine Control Module (ECM)

1. Reconnect the Battery:

   • Reconnect the negative terminal to the battery.

2. Clear the Codes:

   • Use an OBD-II scanner to clear the P0420 code from the ECM.

5. Final Inspection

• Start the engine and let it reach operating temperature.
• Check for any exhaust leaks and verify that the check engine light is off.