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

Solution

1. Preparation

• Gather necessary tools and parts. Ensure the vehicle is secured on a level surface.
• Disconnect the battery to prevent electrical issues while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
• Remove the upstream (pre-catalytic converter) oxygen sensor:
  1. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  2. Install the new O2 sensor, tightening it to the manufacturer’s specified torque (typically around 30 lb-ft).
• Repeat for the downstream (post-catalytic converter) oxygen sensor if it shows signs of failure.

3. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, exhaust pipe cutter (if applicable)
• Raise the vehicle securely using jack stands.
• Disconnect the exhaust pipes connected to the catalytic converter:
  1. Use a socket set to remove bolts or nuts connecting the exhaust.
  2. If necessary, cut exhaust pipes using an exhaust pipe cutter.
• Remove the old catalytic converter:
  1. Unbolt and detach it from the exhaust manifold and the exhaust pipes.
• Install the new catalytic converter:
  1. Position the new converter, ensuring proper orientation.
  2. Secure it using the existing bolts or new hardware as needed, torquing to specifications.
• Reconnect the exhaust pipes as per the manufacturer’s specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use an OBD-II scanner to clear the P0420 code from the ECU.