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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.
• Allow the engine to cool down completely before starting work.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:
   • Locate the upstream oxygen sensor (usually before the catalytic converter).
   • Use an oxygen sensor socket to remove the sensor.
2. Install the new upstream oxygen sensor:
   • Apply anti-seize compound on the sensor threads if required.
   • Torque to the manufacturer's specifications (typically around 30 lb-ft).
3. Repeat for the downstream oxygen sensor if needed:
   • Follow the same procedure for the downstream sensor.

3. Inspect and Replace the Catalytic Converter

1. Remove the exhaust components:
   • Loosen and remove any bolts or clamps securing the catalytic converter.
   • Carefully detach the catalytic converter from the exhaust system.
2. Install the new catalytic converter:
   • Position the new catalytic converter and align it with the exhaust pipes.
   • Secure with bolts or clamps, torquing to specifications (typically around 30-40 lb-ft).
3. Reattach any heat shields or brackets if applicable.

4. Final Checks

1. Reconnect the battery.
2. Start the engine and let it idle for a few minutes.
3. Check for any exhaust leaks around the installed components.