how to fix P0420 code on 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 ignition is off.
• Disconnect the battery to prevent any electrical issues.

2. Inspect and Repair Exhaust System

• Sub-step 1: Raise the vehicle using a jack and secure it with jack stands.
• Sub-step 2: Visually inspect the entire exhaust system for cracks, holes, or loose connections.
• Sub-step 3: If leaks are found, replace the damaged sections using exhaust repair clamps or weld as necessary.

3. Test and Replace Oxygen Sensors

• Sub-step 1: Locate the upstream and downstream oxygen sensors on the exhaust system.
• Sub-step 2: Disconnect the electrical connectors from both sensors.
• Sub-step 3: Use a socket wrench to remove the sensors from the exhaust system.
• Sub-step 4: Install new oxygen sensors, ensuring they are tightened to the manufacturer's specifications (typically around 30 lb-ft).
• Sub-step 5: Reconnect the electrical connectors and ensure they are secure.

4. Replace Catalytic Converter (if necessary)

• Sub-step 1: If the catalytic converter is determined to be faulty based on temperature readings or age, remove it by unbolting the flanges connecting it to the exhaust system.
• Sub-step 2: Install the new catalytic converter and tighten the bolts to the manufacturer’s specifications (usually around 30 lb-ft).
• Sub-step 3: Reconnect any supporting brackets or sensors that were disconnected during removal.

5. Reconnect Battery and Clear Codes

• Sub-step 1: Reconnect the vehicle's battery.
• Sub-step 2: Use the OBD-II scanner to clear the P0420 code from the vehicle's memory.
• Sub-step 3: Start the vehicle and allow it to run for a few minutes to ensure proper functioning.