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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.
• Allow the exhaust system to cool down before starting work.

2. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from the oxygen sensors.
  3. Use the O2 sensor socket to remove the faulty sensors from the exhaust system.
  4. Apply anti-seize compound on the threads of the new oxygen sensors.
  5. Install the new oxygen sensors and torque them to the manufacturer’s specifications (usually around 30 lb-ft).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter, replacement catalytic converter.
• Sub-steps:
  1. Inspect the catalytic converter for physical damage.
  2. If damage is present, remove the nuts/bolts securing the catalytic converter to the exhaust system using the socket set.
  3. Cut the exhaust pipes if necessary to remove the old catalytic converter.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
  5. Secure the catalytic converter with new gaskets and bolts, torquing them to the manufacturer’s specifications.

4. Clear Error Codes

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