how to fix P0304 code on my Porsche Cayenne E3 (2018-Present)

Learn how to diagnose and fix P0304 cylinder 4 misfire in Porsche Cayenne E3. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the engine to cool before beginning any work.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Use a spark plug socket and ratchet to remove the spark plug from cylinder 4.
• Inspect the old spark plug for wear; replace it with a new spark plug that meets manufacturer specifications (e.g., NGK or Bosch).
• Torque the new spark plug to the manufacturer’s specifications (typically around 20 Nm).

3. Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil on cylinder 4.
• Remove the ignition coil by unscrewing the retaining bolts.
• Install the new ignition coil, ensuring it is seated properly.
• Reconnect the electrical connector securely.

4. Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 4.
• Use a multimeter to check the resistance of the fuel injector (should match manufacturer specs).
• If the injector is faulty, remove it using an appropriate tool and replace it with a new one.
• Reconnect the fuel injector and ensure all connections are secure.

5. Compression Test

• Remove the spark plug from cylinder 4.
• Insert a compression tester and crank the engine to take a reading.
• Compare the compression reading to the manufacturer’s specified range.
• If low, further investigation into possible internal engine issues may be required.