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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid electrical shorts during the repair process.

2. Inspect and Replace Oxygen Sensors (if necessary)

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

• Remove the upstream oxygen sensor:

  • Locate the upstream O2 sensor (before the catalytic converter).
  • Use the O2 sensor socket to unscrew the sensor from the exhaust manifold.

• Install the new oxygen sensor:

  • Apply anti-seize compound to the threads of the new sensor.
  • Screw the new sensor into place and tighten it to manufacturer specifications (usually around 30 ft-lbs).

• Repeat the process for the downstream oxygen sensor (after the catalytic converter), if it also shows faults.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust clamp tool
• Raise the vehicle securely on jack stands to access the exhaust system.
• Remove the exhaust clamps holding the catalytic converter in place.
• Detach the catalytic converter from the exhaust pipes:
  • Use the socket set to remove bolts or nuts securing the converter to the exhaust system.
• Install the new catalytic converter:
  • Position the new catalytic converter in place, ensuring all gaskets are properly aligned.
  • Reattach the exhaust pipes and secure with clamps or bolts to the manufacturer’s torque specifications (typically around 30-40 ft-lbs).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the system.
• Start the vehicle and allow it to reach operating temperature.