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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before proceeding with repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Use a socket wrench to remove the upstream oxygen sensor (before the catalytic converter).
   • Tools Required: Oxygen sensor socket, ratchet, torque wrench.
3. Install the new upstream oxygen sensor and tighten it to the manufacturer's specifications (typically around 30-40 ft-lbs).
4. Repeat the process for the downstream oxygen sensor (after the catalytic converter).
5. Ensure all electrical connections are secure.

3. Inspect and Replace Catalytic Converter

1. If the oxygen sensors are functioning correctly and the code persists, inspect the catalytic converter for damage or clogging.
2. Use a socket set to remove the bolts securing the catalytic converter to the exhaust system.
3. Carefully detach the catalytic converter from the exhaust system.
4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
5. Torque the bolts to the manufacturer's specifications (usually around 25-35 ft-lbs).

4. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Clear the error codes using the OBD-II scanner.