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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface with the parking brake engaged.
• Disconnect the battery to prevent electrical issues during the repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench.
• Remove the oxygen sensors using the appropriate socket.
  • Sub-steps:
    1. Disconnect the electrical connectors from the O2 sensors.
    2. Use a socket wrench to unscrew the sensors from the exhaust system.
    3. Install new oxygen sensors and torque them to the manufacturer’s specifications (typically around 30 Nm).
    4. Reconnect the electrical connectors securely.

3. Examine and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust gaskets, torque wrench.
• Safely elevate the vehicle to access the catalytic converter.
  • Sub-steps:
    1. Remove the exhaust bolts connecting the catalytic converter to the exhaust system.
    2. Carefully detach the catalytic converter from its mounts.
    3. Inspect for any damage or excessive clogging.
    4. If replacement is necessary, install the new catalytic converter along with new gaskets.
    5. Torque the bolts to the recommended specifications (check manufacturer guidelines).

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle’s battery.
• Use the OBD-II scanner to clear the P0420 fault code.
• Start the vehicle and allow it to reach operating temperature.