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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical short circuits.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, anti-seize compound.
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Use the O2 sensor socket to remove the upstream oxygen sensor.
  3. Inspect the sensor for damage; if worn or faulty, replace it with a new unit.
  4. Apply anti-seize compound to the threads of the new sensor and install, tightening to the manufacturer’s specified torque.
  5. Repeat the process for the downstream oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, jack and jack stands, exhaust hanger removal tool.
• Sub-steps:
  1. Raise the vehicle using a jack and secure with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Inspect for physical damage such as dents or rust; also, check for clogging by tapping lightly and listening for rattling.
  4. If damaged, remove the exhaust bolts using a socket set and disconnect any exhaust hangers with an exhaust hanger removal tool.
  5. Install the new catalytic converter, securing it with bolts and ensuring proper alignment.
  6. Lower the vehicle and reconnect the negative battery terminal.