how to fix P0420 code in Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, jack and jack stands, safety goggles, gloves.
• Clear any existing error codes from the vehicle’s computer using the OBD-II scanner.
• Ensure the vehicle is parked on a level surface and is in "Park" mode. Disconnect the 12V battery to prevent any electrical issues during repairs.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors (usually found in the exhaust system).
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use the appropriate socket to remove the sensors from the exhaust system.
  4. Install the new oxygen sensors and torque them to the manufacturer's specifications (typically around 30-40 ft-lbs).
  5. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. If the catalytic converter shows signs of damage or if the oxygen sensors do not resolve the code, remove the exhaust components leading to the catalytic converter.
  2. Use a socket set to unbolt the catalytic converter from its mounting points.
  3. Inspect the mounting gaskets and replace if worn or damaged.
  4. Install the new catalytic converter, ensuring it is properly aligned, and torque the bolts to the specified torque values (usually around 30-40 ft-lbs).
  5. Reinstall any exhaust components that were removed, ensuring all connections are secure.

4. Final Checks

• Reconnect the 12V battery.
• Start the vehicle and allow it to reach operating temperature.
• Check for any exhaust leaks and ensure that the system is functioning properly.