how to fix code P0420 in my 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 parking brake is engaged.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

1. Locate the upstream and downstream oxygen sensors on the exhaust system.
2. Use a socket wrench to carefully remove the sensors.
3. Inspect the connectors for corrosion or damage.
4. If sensors are faulty, install new oxygen sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Torque the sensors to manufacturer specifications (typically around 30-40 Nm).
5. Reconnect the electrical connectors for the sensors.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. Remove the exhaust heat shield if applicable.
2. Unbolt the catalytic converter from the exhaust system using a socket set.
3. Inspect the old catalytic converter for any signs of damage or blockage.
4. Install the new catalytic converter:
   • Ensure proper alignment with the exhaust pipes.
   • Torque the bolts to manufacturer specifications (typically around 30-40 Nm).
5. Reinstall the exhaust heat shield if removed.

4. Reconnect Battery and Reset Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.