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

• •Check engine light illuminated
• •Decreased fuel efficiency
• •Increased exhaust emissions
• •Engine performance issues (e.g., loss of power or acceleration)
• •Unusual engine noises (e.g., rattling or hissing)

1. 1Scan the vehicle's onboard diagnostics using an OBD-II scanner to confirm the P0420 code and check for any additional codes.
2. 2Inspect the exhaust system visually for any signs of damage, leaks, or loose connections.
3. 3Check the catalytic converter temperature with an infrared thermometer to ensure the inlet and outlet temperatures are significantly different.
4. 4Examine the oxygen sensors (pre-catalytic and post-catalytic) for proper operation and signs of wear or damage.
5. 5Inspect all related wiring and connectors for fraying, corrosion, or loose connections.
6. 6Perform a smoke test on the exhaust system to check for leaks.

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
• •O2 sensor socket
• •Ratchet
• •Torque wrench
• •Wrench set
• •Exhaust pipe cutter

• •Oxygen sensors (pre-catalytic and post-catalytic)
• •Catalytic converter (if needed)