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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle battery to ensure safety.
• Raise the vehicle using jack stands to access the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
• Using the O2 sensor socket, carefully unscrew the sensors from their respective locations.
• Inspect the wiring and connectors for damage; replace if needed.
• Install new oxygen sensors and torque to manufacturer specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed)
• Inspect the catalytic converter visually for any signs of physical damage or clogging.
• If replacement is needed, use an exhaust pipe cutter to remove the old catalytic converter.
• Install the new catalytic converter, ensuring proper alignment and sealing.
• Torque the bolts to the manufacturer's specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle battery.
• Use the OBD-II scanner to clear any diagnostic trouble codes from the ECM.