what does P0420 code mean for my Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's 12V battery to ensure safety while working on electrical components.

2. Inspect and Clean O2 Sensors

• Remove the upstream and downstream oxygen sensors using a socket wrench.
• Clean the sensors with a suitable cleaner or replace them if they are damaged.
• Reinstall the sensors, ensuring they are properly torqued to prevent leaks.

3. Check Catalytic Converter

• Inspect the catalytic converter visually for any signs of external damage or clogging.
• If necessary, replace the catalytic converter:
  • Remove the exhaust pipes connected to the catalytic converter using a socket set.
  • Unbolt the catalytic converter from its mounting points.
  • Install the new catalytic converter, tightening bolts to manufacturer specifications (usually around 30-40 lb-ft).
  • Reattach exhaust pipes and ensure all connections are secure.

4. Reconnect Battery and Clear Codes

• Reconnect the 12V battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the vehicle and allow it to reach operating temperature.