my Tesla Model S Original (2012-2020) has a check engine light for P0420

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

Solution

1. Preparation

• Gather tools and components required for the repair.
• Disconnect the battery to ensure safety while working on the vehicle's electrical system.

2. Inspect Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter.
• Remove the oxygen sensor connectors.
• Use a multimeter to check the voltage output of both pre-catalytic and post-catalytic oxygen sensors.
  • Expected values: Pre-catalytic should fluctuate between 0.1V to 0.9V, while post-catalytic should be more stable.
• If either sensor is faulty, replace it with a new one.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, gasket scraper.
• Remove any clamps or bolts securing the catalytic converter.
• Carefully detach the catalytic converter from the exhaust system.
• Inspect for any physical damage or blockage.
• If replacement is necessary, install the new catalytic converter using new gaskets.
• Torque the bolts to the manufacturer's specifications (typically around 30-40 ft-lbs, but check specific values).

4. Reconnect Components

• Reattach the oxygen sensor connectors.
• Reconnect the battery terminals securely.

5. Reset the Check Engine Light

• Use the OBD-II scanner to clear the error codes after repairs are complete.