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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical issues.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Jack and jack stands
• Safety goggles and gloves

2. Inspect and Replace Oxygen Sensors (if necessary)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the socket set to remove the oxygen sensors from the exhaust system.
  4. Install new oxygen sensors using anti-seize compound on the threads.
  5. Torque the sensors to the manufacturer's specification (typically around 30-40 ft-lbs).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields covering the catalytic converter.
  2. Use the socket set to unbolt the catalytic converter from the exhaust system.
  3. Inspect the flanges and gaskets for wear and replace if necessary.
  4. Install the new catalytic converter, ensuring it fits snugly against the exhaust system.
  5. Torque the bolts to the manufacturer's specifications.
  6. Reinstall any heat shields removed earlier.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Take the vehicle for a test drive to ensure the engine operates smoothly under various conditions.