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

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 tools and parts needed.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative terminal of the battery for safety.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors near the catalytic converter.
2. Using a socket wrench, carefully disconnect the electrical connectors from both sensors.
3. Remove the oxygen sensors using a specialized oxygen sensor socket.
4. Install the new oxygen sensors by threading them into their respective locations and tightening to the manufacturer's specified torque (typically around 30 lb-ft).
5. Reconnect the electrical connectors ensuring a secure fit.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. If the catalytic converter is damaged, prepare to replace it. Remove any heat shields or mounting bolts securing the converter.
2. Carefully detach the catalytic converter from the exhaust system, ensuring not to damage surrounding components.
3. Install the new catalytic converter, aligning it correctly with the exhaust pipes.
4. Secure the converter with the original or new bolts, tightening them to the specified torque (usually around 25 lb-ft).
5. Reinstall any heat shields that were removed.

4. Reconnect Battery and Clear Codes

1. Reconnect the negative terminal of the battery.
2. Use the OBD-II scanner to clear the P0420 code from the system.
3. Perform a short test drive to ensure the check engine light does not return.