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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove Sensors: Use an O2 sensor socket to remove the oxygen sensors from their respective positions.
   • Tools Required: O2 sensor socket, ratchet, and extensions.
3. Inspect Sensors: Check for carbon buildup or damage on the sensors.
4. Install New Sensors: If sensors are faulty, install new ones ensuring they are torqued to manufacturer specifications.

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components: Unbolt the exhaust sections connected to the catalytic converter.
   • Tools Required: Socket set, torque wrench.
2. Remove Catalytic Converter: Unbolt the catalytic converter from the exhaust system.
3. Inspect for Damage: Check the catalytic converter for signs of clogging or physical damage.
4. Install New Catalytic Converter: Position the new catalytic converter and bolt it in place securely, ensuring to torque to specifications.
5. Reattach Exhaust Components: Reassemble any exhaust sections that were removed.

4. Reset the Engine Control Module (ECM)

1. Reconnect Battery: Reconnect the battery terminals.
2. Clear Codes: Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Perform a Test Drive: Drive the vehicle for a short period to allow the system to monitor the catalytic converter's performance.