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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent any electrical issues during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Remove the connectors from both sensors.
  3. Use the O2 sensor socket to remove the sensors.
  4. Install the new oxygen sensors, ensuring they are torqued to manufacturer specifications (typically around 30 ft-lbs).
  5. Reconnect the sensor connectors.

3. Inspect and Clean/Replace Catalytic Converter

• Tools Required: Socket set, exhaust clamp tool, safety glasses, gloves
• Sub-steps:
  1. Inspect the catalytic converter for any physical damage or blockage.
  2. If cleanable, use a catalytic converter cleaner according to product instructions, or if damaged, prepare to replace it.
  3. If replacing, unbolt the old catalytic converter from the exhaust system using the socket set and exhaust clamp tool.
  4. Install the new catalytic converter, ensuring proper fit and sealing.
  5. Torque all bolts to the manufacturer's specifications.

4. Reset ECU

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the vehicle’s battery.
  2. Use the OBD-II scanner to reset the check engine light and clear the P0420 code from the ECU.