how to fix P0421 code in my Genesis G70 IG (2017-2023)

• •Check engine light illuminated
• •Decreased fuel efficiency
• •Poor engine performance or sluggish acceleration
• •Increased emissions
• •Rattling noise from the exhaust system

1. 1Scan for error codes using an OBD-II scanner to confirm P0421 and check for any additional codes.
2. 2Inspect the exhaust system for visible damage or leaks, especially around the catalytic converter.
3. 3Measure the temperature before and after the catalytic converter using an infrared thermometer.
4. 4Check the oxygen sensors (pre-catalytic and post-catalytic) for proper operation and signal output using a multimeter.
5. 5Inspect for any exhaust leaks or issues with the air-fuel mixture that could affect catalyst efficiency.
6. 6Verify that the engine is running at the correct operating temperature by checking coolant temperature readings.

After completing the repair, verify that the issue has been resolved:

• ✓Test the affected component to ensure it functions correctly
• ✓Check for any error codes or warning lights
• ✓Monitor the vehicle for a few days to ensure the issue does not recur

To prevent this issue from occurring again:

• •Follow the manufacturer's recommended maintenance schedule
• •Address warning signs early before they develop into major issues
• •Use quality parts and fluids recommended for your vehicle
• •Keep detailed records of all repairs and maintenance

• •OBD-II scanner
• •Oxygen sensor socket
• •Wrench set
• •Torque wrench
• •Infrared thermometer
• •Socket set
• •Cutting tools
• •Gasket scraper

• •Oxygen sensors (pre-catalytic and post-catalytic)
• •Catalytic converter (if needed)
• •Exhaust gaskets or seals (if required)