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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a flat surface, engage the parking brake, and disconnect the battery to ensure safety.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor (sensor 1) using the O2 sensor socket.
  • Disconnect the electrical connector by pressing the release tab.
  • Remove the sensor by turning it counterclockwise.
• Install the new upstream oxygen sensor and tighten it to the manufacturer's torque specifications (usually around 30 ft-lbs).
• Repeat the process for the downstream oxygen sensor (sensor 2) if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Wrench set, jack and jack stands, exhaust hanger removal tool.
• Raise the vehicle and support it with jack stands.
• Visually inspect the catalytic converter for any signs of damage or clogging.
• If damage is evident, remove the catalytic converter:
  • Loosen and remove bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe.
  • Remove the catalytic converter from the vehicle.
• Install the new catalytic converter and secure it with bolts, tightening to the manufacturer's specifications.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Start the engine and let it reach operating temperature.
• Take the vehicle for a test drive to ensure the check engine light does not return.