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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Allow the exhaust system to cool down before starting work.

2. Inspect and Repair Exhaust Leaks

• Tools Needed: Socket set, torque wrench, exhaust leak detector.
• Inspect the entire exhaust system from the engine to the tailpipe for leaks.
• Use the exhaust leak detector to identify any hissing sounds.
• Tighten any loose connections or replace gaskets as necessary.

3. Replace Faulty Oxygen Sensors (if necessary)

• Tools Needed: O2 sensor socket, torque wrench.
• Locate the upstream and downstream oxygen sensors.
• Disconnect the electrical connectors and unscrew the sensors using the O2 sensor socket.
• Install new oxygen sensors and torque to manufacturer specifications (typically around 30 lb-ft).
• Reconnect the electrical connectors.

4. Replace the Catalytic Converter (if necessary)

• Tools Needed: Socket set, cutting tool for exhaust pipes, welding equipment or exhaust clamps.
• Raise the vehicle securely on jack stands.
• Remove the exhaust pipes connected to the catalytic converter using a socket set.
• If necessary, cut and remove the old catalytic converter.
• Install the new catalytic converter, securing it with clamps or welding as required.
• Reconnect any exhaust pipes and ensure all connections are tight.

5. Reset the Engine Control Module (ECM)

• Reconnect the battery after repairs are completed.
• Use an OBD-II scanner to clear the P0420 code from the ECM.