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

Solution

1. Preparation

• Gather necessary tools and parts before starting the repair.
• Disconnect the battery to prevent electrical shorts and ensure safety.
• Allow the vehicle to cool down if the engine has been running.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench

• Remove the upstream (pre-catalytic converter) oxygen sensor:

  1. Locate the upstream O2 sensor.
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.
  3. Replace it with a new sensor, ensuring it is tightened to the manufacturer's specifications (usually 30-35 ft-lbs).

• Remove the downstream (post-catalytic converter) oxygen sensor:

  1. Locate the downstream O2 sensor.
  2. Unscrew the sensor using the O2 sensor socket.
  3. Install the new sensor and tighten it to the manufacturer's specifications.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter (if necessary), gasket maker
• Lift the vehicle using a jack and secure it with jack stands.
• Remove the exhaust system components as needed to access the catalytic converter:
  1. Unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
  2. If necessary, cut the exhaust pipe to remove the old catalytic converter.
• Install the new catalytic converter:
  1. Position the new catalytic converter and secure it with bolts.
  2. Use gasket maker to seal any connections if required.
  3. Ensure all bolts are torqued to the manufacturer's specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code and any other related codes.