how to fix the P0300 code on my Tesla Model S Plaid/Refresh (2021-present)

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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, fuel pressure gauge, torque wrench.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover (if applicable) using the appropriate socket.
  2. Disconnect the ignition coil connectors.
  3. Remove the ignition coils using a socket set.
  4. Extract the spark plugs using a spark plug socket.
  5. Inspect the spark plugs for signs of wear or damage; replace if needed.
  6. Install new spark plugs, torquing them to the manufacturer’s specifications (typically 18-22 lb-ft).
  7. Reinstall the ignition coils and reconnect the connectors.

3. Test and Replace Ignition Coils

• Sub-steps:
  1. Use a multimeter to check each ignition coil’s resistance.
  2. Replace any coils that show resistance outside of the manufacturer's specifications.
  3. Reinstall any replaced coils and ensure connections are secure.

4. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the engine cover if necessary for access.
  2. Visually inspect each fuel injector for cracks or leaks.
  3. If injectors are clogged, use a cleaning solution or replace them if necessary.
  4. Reassemble any components removed during inspection.

5. Test Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Attach a fuel pressure gauge to the test port.
  3. Turn the ignition to the "ON" position without starting the engine to check fuel pressure.
  4. Compare the reading against the manufacturer’s specifications.
  5. If pressure is low, check the fuel pump and fuel filter for issues.

6. Inspect for Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to check for leaks around the intake manifold.
  3. Repair or replace any damaged hoses or seals.