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

Solution

1. Preparation

• Gather all required tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the pre-catalytic converter oxygen sensor:
  1. Unplug the electrical connector.
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
• Install the new oxygen sensor:
  1. Apply anti-seize compound to the threads of the new sensor.
  2. Screw it into place and tighten to the manufacturer's specified torque (usually between 30-40 lb-ft).
• Repeat the process for the post-catalytic converter oxygen sensor if needed.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust cutter, gasket scraper
• Raise the vehicle using a jack and secure it with jack stands.
• Remove the catalytic converter:
  1. Cut the exhaust pipes using the exhaust cutter if they are rusted or difficult to remove.
  2. Unbolt the catalytic converter from its mounting points.
• Install the new catalytic converter:
  1. Clean the mating surfaces with a gasket scraper.
  2. Position the new catalytic converter and secure it with bolts to the specified torque.
• Reconnect any exhaust hangers or brackets removed during installation.

4. Clear Error Codes and Test Drive

• Reconnect the battery.
• Use the OBD-II scanner to erase the trouble codes.
• Start the vehicle and allow it to reach operating temperature.
• Take the car for a test drive to ensure the check engine light does not reappear and the vehicle operates normally.