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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, jack and jack stands, safety goggles, gloves.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Repair Exhaust Leaks

• Sub-steps:
  1. If any leaks are found in the exhaust system, repair or replace the affected sections.
  2. Use exhaust sealant or replace gaskets as needed.
  3. Tighten any loose connections.

3. Replace Oxygen Sensors (if faulty)

• Sub-steps:
  1. Disconnect the battery to prevent any electrical shorts.
  2. Locate the upstream and downstream oxygen sensors.
  3. Unplug the electrical connectors and remove the sensors using a wrench.
  4. Install new oxygen sensors and reconnect the electrical connectors.
  5. Reconnect the battery.

4. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Disconnect the exhaust pipe from the catalytic converter using a socket set.
  3. Remove any mounting bolts or brackets securing the catalytic converter.
  4. Install the new catalytic converter and secure it with bolts.
  5. Reconnect the exhaust pipe.

5. Clear Error Codes

• Use the OBD-II scanner to clear the P0420 code and test drive the vehicle to check if the code returns.