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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Raise the vehicle securely on jack stands.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, and torque wrench.
• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors from the exhaust system.
  4. Install new O2 sensors by hand-tightening and then using a torque wrench to tighten to the manufacturer’s specifications (typically around 30 Nm).
  5. Reconnect electrical connectors to the new sensors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting torch (if necessary).
• Sub-steps:
  1. Inspect the catalytic converter for any visible signs of damage or blockage.
  2. If replacement is necessary, unbolt the catalytic converter from the exhaust pipes.
  3. Remove any exhaust hangers or brackets holding the converter in place.
  4. Install the new catalytic converter, ensuring proper alignment.
  5. Torque all bolts to the manufacturer's specifications (typically around 40-50 Nm).
  6. Reconnect any exhaust hangers or brackets.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the PCM.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not reappear.