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

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, jack and jack stands, smoke machine (optional).
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the negative battery terminal to avoid electrical issues while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use a socket wrench to remove the sensors from the exhaust system.
  4. Install new oxygen sensors and torque them to the manufacturer's specifications.
  5. Reconnect the electrical connectors to the sensors.

3. Examine and Replace Catalytic Converter

• Sub-steps:
  1. Using a jack and jack stands, lift the vehicle to access the exhaust system.
  2. Remove the bolts securing the catalytic converter to the exhaust system using a socket set.
  3. Carefully lower and remove the catalytic converter from the vehicle.
  4. Inspect the new catalytic converter for any damage before installation.
  5. Install the new catalytic converter and torque the bolts to the manufacturer's specifications.
  6. Reconnect any exhaust hangers or heat shields as necessary.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the vehicle and let it idle for a few minutes to ensure the system stabilizes.