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

Learn how to diagnose and fix P0420 exhaust system issue 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 to ensure safety during repairs.
• Allow the vehicle to cool down before proceeding.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust manifold and catalytic converter.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use an O2 sensor socket to remove the sensors from their mounting locations.
  4. Install new oxygen sensors, ensuring they are properly threaded and tightened to the manufacturer's torque specifications (typically around 30 ft-lbs).
  5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. If testing indicates a faulty catalytic converter, unbolt the exhaust system from the catalytic converter.
  2. Remove the old catalytic converter from the exhaust system.
  3. Install the new catalytic converter, ensuring that all gaskets are in good condition and properly seated.
  4. Torque the bolts to the manufacturer’s specifications (usually around 25-30 ft-lbs).
  5. Reconnect the exhaust system and ensure there are no leaks.

4. Clear Diagnostic Codes

• Sub-steps:
  1. Reconnect the vehicle's battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  3. Start the vehicle and allow it to reach operating temperature to reset the system.