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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, multimeter
• Remove the upstream oxygen sensor by using the O2 sensor socket.
• Check the resistance of the sensor with a multimeter; if it’s out of spec, replace it with a new sensor.
• Install the new sensor and torque it to manufacturer's specifications (usually around 30-40 ft-lbs).

3. Examine and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust gasket sealant
• Remove the bolts securing the catalytic converter to the exhaust system using the socket set.
• Inspect the catalytic converter for any signs of damage or clogging; if damaged, replace it.
• Install the new catalytic converter and secure it with bolts, torquing them to the manufacturer's specifications (typically around 30-40 ft-lbs).
• Apply exhaust gasket sealant to ensure a proper seal.

4. Reconnect and Test

• Reconnect the battery.
• Clear the trouble codes using the OBD-II scanner.
• Start the engine and let it run for a few minutes to ensure the system is operating properly.