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

Solution

1. Preparation

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

2. Inspect Exhaust System

• Tools Required: Visual inspection tools.
• Instructions:
  • Visually inspect the exhaust system for any visible damage or leaks.
  • Pay special attention to joints and areas around the catalytic converter.
  • If any leaks are found, repair them with appropriate exhaust sealant or replace damaged sections.

3. Test Oxygen Sensors

• Tools Required: Multimeter.
• Instructions:
  • Locate the upstream and downstream oxygen sensors on the exhaust system.
  • Disconnect the electrical connectors from both sensors.
  • Use the multimeter to check the voltage output of the upstream sensor while the engine is running; it should fluctuate between 0.1 to 0.9 volts.
  • Repeat the process for the downstream sensor; it should have a more stable voltage. If readings are out of spec, replace the faulty sensor.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust clamp tool.
• Instructions:
  • If testing indicates a malfunctioning catalytic converter, it will need to be replaced.
  • Remove the exhaust nuts or bolts securing the catalytic converter to the exhaust system.
  • Carefully detach the catalytic converter and replace it with a new unit.
  • Re-secure it using new gaskets and torque the bolts/nuts to the manufacturer's specifications.

5. Reconnect Battery and Clear Error Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the system.
• Start the vehicle to ensure the Check Engine Light does not reappear.