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

Solution

1. Preparation

• Gather required tools and parts.
• Park the vehicle on a level surface, engage the parking brake, and disconnect the battery.
• Allow the engine to cool down before inspection.

2. Inspect and Replace Components

A. Catalytic Converter Inspection

• Tools Required: Socket set, flashlight
• Remove any heat shields if present using a socket set.
• Inspect the catalytic converter for any physical damage, such as dents or holes. If damaged, replace the catalytic converter.

B. Oxygen Sensor Inspection

• Tools Required: Oxygen sensor socket, multimeter
• Disconnect the wiring harness from the upstream and downstream oxygen sensors.
• Use an oxygen sensor socket to remove the sensors.
• Test the sensors with a multimeter to ensure they are functioning properly. Replace any faulty sensors.

3. Exhaust System Repair

• Tools Required: Exhaust pipe cutter, clamps, and welding tools (if needed)
• Check for leaks in the exhaust system using a smoke test or listening for hissing sounds.
• Repair or replace any damaged sections of the exhaust system, ensuring all connections are secure.

4. Clear Codes and Test Drive

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code.
• Conduct a test drive to ensure the vehicle operates correctly and monitor for any reoccurrence of the code.