my Genesis G70 IG (2017-2023) shows a check engine light with code P0420 what does it mean

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the vehicle to cool completely before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor (pre-catalytic converter) and inspect for any damage or contamination.
• If faulty, replace it with a new sensor, ensuring it's torqued to manufacturer specifications (usually around 30 lb-ft).
• Repeat for the downstream oxygen sensor (post-catalytic converter) if needed.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary).
• Remove the exhaust pipes connected to the catalytic converter, noting the order of disassembly.
• Inspect the catalytic converter for signs of overheating or blockage.
• If damaged, replace the catalytic converter with an OEM or equivalent part, ensuring proper fitment.
• Reassemble the exhaust system, torquing bolts to manufacturer specifications (refer to service manual).

4. Reset the Engine Control Module (ECM)

• After repairs, reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code and reset the check engine light.