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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, jack and jack stands, socket set, torque wrench.
• Allow the vehicle to cool down before starting work. Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use a socket wrench to disconnect the electrical connectors from both sensors.
3. Remove the sensors using an oxygen sensor socket.
4. Install the new oxygen sensors by reversing the removal steps, ensuring they are properly torqued to manufacturer specifications (typically around 30 lb-ft).
5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Raise the vehicle using a jack and secure it with jack stands.
2. Visually inspect the catalytic converter for physical damage or excessive soot buildup.
3. If replacement is needed, unbolt the catalytic converter from the exhaust system using a socket set. Carefully remove it from the vehicle.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Torque the bolts to manufacturer specifications (usually around 30 lb-ft).
6. Reconnect any exhaust components that were removed.

4. Reconnect Battery and Clear Codes

1. Reconnect the vehicle’s battery.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the vehicle and let it idle to ensure the system is functioning correctly.