my Tesla Model S Plaid/Refresh (2021-present) has a check engine light and a P0420 code, what to do?

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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the parking brake is engaged.
• Disconnect the 12V battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Access the oxygen sensors:
   • Locate the upstream and downstream oxygen sensors in the exhaust system.
   • Remove any heat shields or covers if necessary.
2. Remove the sensors:
   • Use an oxygen sensor socket to carefully unscrew the sensors from their locations.
   • Take care not to damage the wiring.
3. Install new sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Install the new oxygen sensors and torque them to the manufacturer’s specifications (usually around 30 ft-lbs).
4. Reconnect electrical connectors:
   • Ensure all connectors are secure and free of corrosion.

3. Inspect and Replace Catalytic Converter (if required)

1. Examine the catalytic converter:
   • Inspect for physical damage, clogs, or signs of overheating.
2. Remove the old catalytic converter:
   • Disconnect any bolts or clamps securing the catalytic converter to the exhaust system.
   • Remove the converter from its mounts.
3. Install the new catalytic converter:
   • Position the new catalytic converter and secure it with bolts or clamps.
   • Torque bolts to manufacturer specifications (usually around 30-50 ft-lbs).
4. Reconnect exhaust system:
   • Ensure all parts of the exhaust system are reconnected correctly and securely.

4. Clear Codes and Test Drive

1. Reconnect the battery:
   • Ensure all connections are secure before reconnecting the battery.
2. Use the OBD-II scanner:
   • Clear the P0420 code from the vehicle’s computer.
3. Test drive the vehicle:
   • Drive the vehicle in various conditions to ensure the check engine light does not return and the vehicle performs correctly.