how to fix P0300 misfire code in Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0300 engine misfire in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Gather tools and parts needed for the repair.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, and spark plug socket.
• Remove the engine cover if applicable to access ignition components.
• Disconnect the ignition coils from their harness and unbolt them using the socket set.
• Remove the old spark plugs using the spark plug socket, checking for wear or damage.
• Install new spark plugs, ensuring they are gapped correctly per manufacturer specifications (typically 0.028 inches for Tesla).
• Reinstall ignition coils and secure them with the appropriate torque (usually around 15 Nm).

3. Check and Repair Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail to check for proper fuel pressure (refer to service manual for specific pressure values).
• If pressure is inadequate, inspect the fuel pump and fuel filter for clogs or failures.
• Replace any faulty components as necessary, ensuring all connections are secure.

4. Conduct a Vacuum Leak Test

• Inspect all vacuum hoses for cracks or disconnections.
• Use a smoke machine or carburetor cleaner around suspected areas while the engine is running to identify leaks.
• Seal or replace any leaking hoses or gaskets found during inspection.

5. Software Update

• Use Tesla's service tool to check for any available software updates.
• If updates are available, follow the instructions to apply them to the vehicle.