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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust thermometer.
• Ensure the vehicle is on a level surface and the ignition is off.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Remove the sensors using a socket wrench.
  4. Install new oxygen sensors in the same position and torque to manufacturer specifications (usually around 30 ft-lbs).
  5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  1. Locate the catalytic converter and inspect for physical damage or blockage.
  2. If replacement is necessary, disconnect the exhaust pipes connected to the catalytic converter.
  3. Remove mounting bolts using a socket set.
  4. Install the new catalytic converter, ensuring proper alignment with exhaust pipes.
  5. Torque all bolts to the manufacturer’s specifications and reconnect the exhaust system.

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the battery terminals, ensuring tight connections.
  2. Use the OBD-II scanner to clear the P0420 code and any other related codes.
  3. Start the vehicle and allow it to reach operating temperature.