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

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Clean Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Remove the sensors using an oxygen sensor socket or wrench.
  3. Clean the sensors with an appropriate cleaner if they are contaminated.
  4. Reinstall the sensors and ensure they are securely fastened.

3. Check and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. If the catalytic converter is clogged or damaged, remove it from the exhaust system.
  2. Support the vehicle securely on jack stands.
  3. Remove the exhaust bolts and any hangers to detach the catalytic converter.
  4. Install a new catalytic converter, ensuring proper alignment.
  5. Use a torque wrench to tighten bolts to manufacturer specifications.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the ECM.
  3. Take the vehicle for a short drive to allow the system to recheck the catalytic efficiency.