what does it mean when my Tesla Model S Plaid/Refresh (2021-present) shows a P0420 code

• •Check Engine Light illuminated
• •Decreased engine performance
• •Poor fuel economy
• •Increased exhaust emissions
• •Unusual engine noises (e.g., rattling from the exhaust)

1. 1Scan for error codes using an OBD-II scanner to confirm P0420 and check for any related codes.
2. 2Inspect the catalytic converter for physical damage or signs of overheating (e.g., discoloration).
3. 3Check the exhaust system for leaks or blockages that might affect the catalytic converter's performance.
4. 4Test the oxygen sensors before and after the catalytic converter for proper functionality using a multimeter.
5. 5Inspect the engine air-fuel mixture to ensure it is within specifications (check for vacuum leaks or fuel delivery issues).
6. 6Review the engine control module (ECM) software version to ensure it is up to date.

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
• •Socket set
• •Torque wrench
• •Multimeter
• •Flathead screwdriver
• •Phillips screwdriver

• •Replacement oxygen sensors (if necessary)
• •Replacement catalytic converter (if necessary)
• •Exhaust gaskets and hardware (if necessary)