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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect Exhaust System

• Sub-steps:
  • Visually inspect the entire exhaust system for cracks, holes, or loose connections.
  • Use a smoke test to identify any leaks in the exhaust system.
• Tools Required: Smoke machine (if applicable)

3. Test Oxygen Sensors

• Sub-steps:
  • Locate the upstream and downstream oxygen sensors.
  • Disconnect each sensor's electrical connector.
  • Use a multimeter to measure the output voltage while the engine is running; it should fluctuate between 0.1V to 0.9V for the upstream sensor.
• Tools Required: Multimeter

4. Replace Oxygen Sensors (if faulty)

• Sub-steps:
  • Remove the faulty oxygen sensor using an oxygen sensor socket.
  • Apply anti-seize compound to the threads of the new sensor.
  • Install the new oxygen sensor and reattach the electrical connector.
• Torque Value: Follow manufacturer specifications for oxygen sensor installation.

5. Inspect and Replace Catalytic Converter (if needed)

• Sub-steps:
  • Check the catalytic converter for physical damage or blockage.
  • If necessary, remove the catalytic converter by unbolting it from the exhaust manifold and downstream pipe.
  • Install the new catalytic converter, ensuring proper alignment and secure fastening.
• Tools Required: Socket set, torque wrench
• Torque Value: Follow manufacturer specifications for catalytic converter installation.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's memory.