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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Ensure the engine is cool to avoid burns.

2. Inspect and Replace Oxygen Sensors

• Remove the upstream and downstream oxygen sensors:
  1. Use an O2 sensor socket or wrench.
  2. Disconnect the wiring harness carefully.
• Inspect sensors for damage or contamination.
• Replace with new OEM or high-quality aftermarket sensors if necessary.

3. Inspect and Replace Catalytic Converter

• Check the exhaust system and remove the catalytic converter:
  1. Support the vehicle securely on jack stands.
  2. Unbolt the catalytic converter from the exhaust pipes using a socket set.
  3. Remove any heat shields as necessary.
• Install the new catalytic converter:
  1. Align the new converter with the exhaust pipes.
  2. Use new gaskets and bolts as required.
  3. Torque the bolts to manufacturer specifications (refer to service manual for exact torque values).

4. Reconnect Battery and Clear Codes

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

5. Test the Repair

• Start the engine and let it idle.
• Monitor for any check engine lights and ensure proper exhaust flow.