how to fix the P0420 code on my Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, exhaust temperature gauge.
• Ensure the vehicle is parked on a level surface, and the parking brake is engaged.
• Disconnect the vehicle's battery to prevent electrical shock during repairs.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the appropriate socket to remove the sensors from the exhaust manifold and catalytic converter.
  4. Install new oxygen sensors and torque them to the manufacturer specifications (typically around 32 ft-lbs).
  5. Reconnect the electrical connectors securely.

3. Assess and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields or covers obstructing access to the catalytic converter.
  2. Disconnect the exhaust pipes from both ends of the catalytic converter using the socket set.
  3. Remove the catalytic converter from its mounting brackets.
  4. Install the new catalytic converter, ensuring proper alignment and fitting.
  5. Torque all connections to the manufacturer's specifications (check for specific values in the service manual).
  6. Reinstall any heat shields or covers removed during the process.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and allow it to run until it reaches normal operating temperature.