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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-cat) oxygen sensor by using an O2 sensor socket and ratchet. Check for any signs of corrosion or damage.
• Install a new oxygen sensor (ensure it is the correct part for the Genesis G70 IG) and torque it to the manufacturer's specification (typically around 30 lb-ft).
• Repeat the process for the downstream (post-cat) oxygen sensor if it has been diagnosed as faulty.

3. Check and Replace Catalytic Converter

• Tools Required: Socket set, exhaust hanger removal tool, jack stands.
• Remove the exhaust system components leading to the catalytic converter. Take care to support the exhaust system properly.
• Detach the catalytic converter from its mounts and exhaust pipes, ensuring to keep all gaskets for replacement.
• Install a new catalytic converter, ensuring to replace any gaskets or seals. Torque all bolts to the manufacturer's specification.
• Reattach the exhaust system components and check for proper alignment.

4. Clear Codes and Test Drive

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
• Perform a test drive under various conditions to allow the vehicle to re-enter readiness monitors.