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

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.

2. Remove the Oxygen Sensors:

   • Use an oxygen sensor socket to unscrew the sensors from their respective locations.
   • Disconnect the electrical connectors from each sensor.

3. Install New Oxygen Sensors:

   • Apply anti-seize compound to the threads of the new sensors.
   • Screw the new sensors into place and reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

1. Remove the Exhaust Components:

   • Use a socket set to detach the exhaust pipes connected to the catalytic converter.
   • Support the exhaust system to prevent it from falling.

2. Remove the Catalytic Converter:

   • Unbolt the catalytic converter from its mounting brackets.
   • Carefully remove the catalytic converter from the vehicle.

3. Install a New Catalytic Converter:

   • Position the new catalytic converter in place.
   • Secure it with bolts to the mounting brackets.

4. Reconnect Exhaust Components:

   • Reattach the exhaust pipes to the catalytic converter and tighten the bolts to the manufacturer’s torque specifications.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.