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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, jack and jack stands, safety glasses, gloves.
• Ensure the vehicle is parked on a flat surface and the engine is off.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Disconnect the Battery: Disconnect the negative terminal of the battery to prevent electrical shorts.
3. Remove Oxygen Sensors: Use a socket wrench to carefully unscrew the oxygen sensors from their locations.
4. Install New Oxygen Sensors: Apply anti-seize compound on the threads of the new sensors and install them, tightening to manufacturer specifications (typically 30-40 Nm).
5. Reconnect the Battery: Reconnect the negative battery terminal.

3. Examine and Replace the Catalytic Converter (if necessary)

1. Jack Up the Vehicle: Use a jack to lift the vehicle and secure it with jack stands.
2. Remove Exhaust Components: Use a socket set to detach any exhaust components connected to the catalytic converter (ensure you keep any gaskets for reuse or replacement).
3. Inspect the Catalytic Converter: Check for cracks, dents, or blockage. If damaged, proceed to replace it.
4. Install New Catalytic Converter: Position the new catalytic converter and secure it with bolts. Use a torque wrench to tighten bolts to manufacturer specifications.
5. Reassemble Exhaust System: Reconnect all removed exhaust components and ensure there are no leaks.