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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, infrared thermometer, socket set, torque wrench, safety goggles, gloves.
• Gather all necessary tools and safety equipment. Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Inspect and Test Oxygen Sensors

• Disconnect the battery to ensure safety.
• Locate the upstream and downstream oxygen sensors.
• Remove the connectors and use a multimeter to check the voltage output:
  • Upstream should fluctuate between 0.1V and 0.9V.
  • Downstream should be more stable, around 0.5V.
• If readings are outside these ranges, replace the faulty oxygen sensor.

3. Check the Catalytic Converter

• Use the infrared thermometer to measure the temperature at the inlet and outlet of the catalytic converter.
• A difference of more than 100°F (38°C) indicates the converter may be faulty.
• If the catalytic converter is defective, proceed to replace it.

4. Replace the Catalytic Converter (if necessary)

• Disconnect any sensors or lines connected to the catalytic converter.
• Remove any bolts or clamps securing the catalytic converter to the exhaust system.
• Install the new catalytic converter and secure it with bolts, ensuring proper torque specifications are followed (consult service manual).
• Reconnect any sensors or lines that were disconnected.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the system.
• Start the vehicle and allow it to reach operating temperature.