how to fix P0420 code on 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.
• Disconnect the vehicle's battery to ensure safety.
• Allow the vehicle to cool down before starting any work.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Remove the pre-catalytic converter oxygen sensor:
  1. Disconnect the electrical connector.
  2. Use the O2 sensor socket to unscrew the sensor.
• Install the new pre-catalytic converter oxygen sensor:
  1. Apply anti-seize compound to the threads.
  2. Install and torque to manufacturer specifications (usually around 30-40 lb-ft).
• Repeat the process for the post-catalytic converter oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter (if needed), gaskets.
• Remove the catalytic converter:
  1. Disconnect any clamps or bolts securing it to the exhaust system.
  2. If necessary, cut the exhaust pipes using the exhaust pipe cutter.
• Install the new catalytic converter:
  1. Position the new converter in place and secure it with new gaskets and hardware.
  2. Torque all connections to manufacturer specifications.

4. Reset the Engine Control Unit (ECU)

• Tools Required: OBD-II scanner.
• Connect the OBD-II scanner and clear the P0420 code from the ECU.

5. Final Inspection

• Reconnect the battery and start the vehicle.
• Inspect for any exhaust leaks around the new components.