how to fix P0420 code in Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0420 catalytic converter issues in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery before starting any repair work.
• Allow the vehicle to cool down if it has been running.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the pre-catalytic and post-catalytic converters' oxygen sensors.
2. Remove the sensors:
   • Use an oxygen sensor socket or appropriate wrench.
   • Carefully disconnect the electrical connector before removal.
3. Install new sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Install the new sensors by threading them into place and securely tightening to manufacturer specifications (typically around 30-40 lb-ft).
4. Reconnect electrical connectors: Ensure all connectors are secure and free from damage.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Check for physical damage: Inspect the catalytic converter for any cracks, dents, or signs of overheating.
2. Remove the catalytic converter:
   • Disconnect the exhaust pipe from the catalytic converter using a socket set.
   • Unbolt any hangers or brackets holding the converter in place.
3. Install the new catalytic converter:
   • Position the new converter in place and secure it with bolts to the exhaust system.
   • Ensure all gaskets are properly seated to prevent leaks.
4. Reconnect exhaust system: Tighten all connections and ensure there are no exhaust leaks.

4. Clear Codes and Test

1. Reconnect the battery: Reconnect the battery terminals ensuring a secure connection.
2. Use the OBD-II scanner: Clear the P0420 code from the ECU.
3. Test drive the vehicle: Take the vehicle for a test drive to ensure the check engine light does not reappear and monitor for any performance issues.