how to fix the P0420 code in my Tesla Model Y Current (2020-present)

Solution

1. Preparation

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

2. Inspect and Repair Exhaust System

• Use a jack and jack stands to lift the vehicle safely.
• Inspect the exhaust pipes for cracks or holes.
• If leaks are found, use exhaust repair tape or replace sections of the exhaust as necessary.

3. Replace Oxygen Sensors (if faulty)

• Locate the upstream and downstream oxygen sensors.
• Use an O2 sensor socket to unscrew the faulty sensor(s).
• Apply anti-seize compound to the threads of the new sensor.
• Install the new sensor(s) and tighten to the manufacturer's specifications (usually around 30 Nm).
• Reconnect any electrical connectors.

4. Replace Catalytic Converter (if necessary)

• If diagnostics confirm the catalytic converter is faulty, remove it by unbolting the flange connections.
• Install the new catalytic converter, ensuring the exhaust gaskets are in good condition.
• Torque the bolts to the manufacturer’s specifications (typically around 40 Nm).
• Reconnect any sensors or components that were removed.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 code from the system.