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

Solution

1. Preparation

• Ensure the vehicle is parked on a flat surface and the parking brake is engaged.
• Disconnect the battery to prevent electrical shorts while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Identify the upstream and downstream oxygen sensors on the exhaust system.

2. Remove the Sensors:

   • Use an O2 sensor socket to unscrew the upstream and downstream oxygen sensors.

3. Install New Sensors:

   • Apply anti-seize compound to the threads of the new sensors.
   • Install the new upstream and downstream oxygen sensors, tightening them to the manufacturer's specifications (usually around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the Exhaust Components:

   • Unbolt the exhaust components connected to the catalytic converter using a socket set.
   • Ensure to support the exhaust system properly to prevent strain.

2. Remove the Catalytic Converter:

   • Unscrew the bolts securing the catalytic converter and remove it from the exhaust system.

3. Install New Catalytic Converter:

   • Position the new catalytic converter in place.
   • Secure it with the bolts and tighten to manufacturer specifications.

4. Reconnect Battery and Clear Codes

1. Reconnect the Battery:

   • Ensure all connections are secure before reconnecting the battery.

2. Clear Error Codes:

   • Use the OBD-II scanner to clear the P0420 code from the system.