how to fix P0420 code on Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the wiring harness from each oxygen sensor.
  3. Use an O2 sensor socket to remove the sensors from the exhaust.
  4. Install new sensors by threading them into place and tightening to the manufacturer's torque specifications (typically around 30 lb-ft).
  5. Reconnect the wiring harness to the new sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields or covers that obstruct access to the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter, using a socket set.
  3. Remove the catalytic converter from its mounting location.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reattach exhaust pipes and torque to manufacturer specifications.

4. Reconnect Battery

• Reconnect the negative battery terminal and ensure it's secure.

5. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and perform a test drive to ensure that the engine operates smoothly without triggering the check engine light.