how to fix P0420 code on Tesla Model Y Current (2020-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, basic hand tools (sockets, wrenches), safety goggles, gloves.
• Ensure the vehicle is parked on a level surface with the engine off and cool. Disconnect the negative battery terminal to avoid electrical shocks.

2. Inspect and Test Oxygen Sensors

• Remove the upstream and downstream oxygen sensors using a sensor socket.
• Use a multimeter to test the voltage output of the upstream sensor should fluctuate between 0.1V and 0.9V while the engine is running.
• If the readings are out of spec, replace the faulty oxygen sensor(s).

3. Inspect Catalytic Converter

• Visually inspect the catalytic converter for any physical damage such as dents or cracks.
• If the converter is damaged or clogged, it will need to be replaced.
• To replace, remove any heat shields or brackets that may obstruct access, then unbolt the catalytic converter from the exhaust system.

4. Install New Components

• Parts Required: New catalytic converter (if needed), new oxygen sensors (if needed), exhaust gaskets.
• Install the new catalytic converter and tighten the bolts to the manufacturer's specifications (typically around 25-30 ft-lbs, but verify for your specific part).
• Reconnect the O2 sensors and ensure they are secured.

5. Clear Codes and Reconnect Battery

• Reconnect the negative battery terminal and use the OBD-II scanner to clear the P0420 code from the system.
• Start the engine and allow it to reach operating temperature.