how to diagnose P0420 code on my Tesla Model S Plaid/Refresh (2021-present)

• •Check engine light illuminated
• •Reduced engine performance
• •Decreased fuel efficiency
• •Unusual exhaust odors
• •Failed emissions test (if applicable)

1. 1Scan for error codes using OBD-II scanner to confirm the P0420 code and check for any additional codes.
2. 2Inspect exhaust system visually for any signs of leaks, damage, or other issues that could affect catalytic converter performance.
3. 3Verify fuel trim readings using the scanner to check for any abnormalities in the air-fuel mixture that could lead to catalytic converter inefficiency.
4. 4Check the oxygen sensors by monitoring their voltage readings; compare pre-catalytic converter and post-catalytic converter sensor data for discrepancies.
5. 5Perform a visual inspection of the catalytic converter for physical damage or signs of overheating.
6. 6Conduct a smoke test to identify any exhaust leaks that may affect the performance of the catalytic converter.

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
• •Socket set
• •Torque wrench
• •Screwdrivers

• •Oxygen sensors (if faulty)
• •Catalytic converter (if replaced)