how to fix P0420 code in Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative battery terminal to ensure safety during repairs.
• Allow the vehicle to cool down before proceeding.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Remove the O2 sensor from the exhaust manifold or catalytic converter using the O2 sensor socket.
• Install the new O2 sensor and torque it to the manufacturer's specifications (typically around 30 ft-lbs).
• Reconnect the electrical connector to the O2 sensor.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary)
• Disconnect the exhaust system from the catalytic converter by removing the bolts using a socket set.
• Inspect the catalytic converter for damage; if it is clogged or damaged, proceed to replace it.
• Remove the old catalytic converter and install the new one, ensuring proper alignment.
• Torque the bolts to the manufacturer's specifications (usually around 25-30 ft-lbs).
• Reconnect the exhaust system.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Perform a test drive to monitor for any reoccurrence of the check engine light.