how to fix P0304 misfire code on Tesla Outback 4th Generation (2010-2014)?

Learn how to diagnose and fix P0304 cylinder 4 misfire in Tesla Outback (2010-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Ensure the engine is cool before starting work.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug

1. Remove the ignition coil from cylinder 4:
   • Use a socket set to remove the bolts securing the coil.
   • Carefully pull the coil out without damaging the connector.
2. Remove the spark plug:
   • Use a spark plug socket to unscrew the spark plug from cylinder 4.
   • Inspect the spark plug for signs of wear or damage; if necessary, replace it with a new one.
3. Install the new spark plug:
   • Apply anti-seize compound to the threads of the new spark plug.
   • Torque the spark plug to the manufacturer's specification (typically around 13-15 lb-ft).
4. Reinstall the ignition coil:
   • Reconnect the connector and secure it with the bolts.

3. Test and Replace Ignition Coil (if necessary)

1. Use a multimeter to test the resistance of the ignition coil:
   • If the resistance is out of specification, replace the ignition coil with a new one.
2. Install the new ignition coil in cylinder 4:
   • Follow the same steps as above to reinstall.

4. Inspect and Clean Fuel Injector

1. Remove the fuel injector for cylinder 4:
   • Disconnect the electrical connector and fuel line (ensure fuel pressure is relieved).
   • Use the appropriate tool to pull out the injector.
2. Clean the injector using a fuel injector cleaner:
   • If necessary, replace the injector with a new one.
3. Reinstall the injector:
   • Ensure proper seating and reconnect the fuel line.

5. Compression Test (if misfire persists)

1. Connect the compression tester to cylinder 4:
   • Remove the spark plug and screw in the tester.
2. Crank the engine and record the compression reading.
3. If the compression is low, further investigation may be needed for internal engine issues.