how to fix P0304 code in Volkswagen Golf MK6 (2009-2014)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on the electrical system.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 4:
  • Unscrew the bolts securing the ignition coil.
  • Carefully pull the ignition coil out of the spark plug well.
• Remove the spark plug:
  • Use a spark plug socket and ratchet to remove the spark plug from cylinder 4.
  • Inspect the old spark plug for wear and carbon buildup.
• Install the new spark plug:
  • Apply anti-seize compound to the threads of the new spark plug (if applicable).
  • Torque the new spark plug to the manufacturer's specification (typically around 20 Nm).
• Reinstall the ignition coil:
  • Push the ignition coil back into place over the spark plug.
  • Secure it with the bolts and reattach the electrical connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil was found to be faulty during inspection, replace it:
  • Follow the same steps as above for removal and installation.
  • Ensure correct torque specifications are followed.

4. Inspect and Clean Fuel Injector

• If the fuel injector is suspected to be clogged:
  • Remove the fuel injector from the rail.
  • Clean the injector using an appropriate cleaning solution or replace it if necessary.
• Reinstall the injector and ensure all connections are secure.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses connected to the intake manifold for any cracks or disconnections.
• Replace any damaged hoses and ensure all connections are tight.

Tools Required:

• OBD-II scanner
• Socket set (including spark plug socket)
• Torque wrench
• Compression tester
• Fuel injector cleaning kit (if necessary)
• Basic hand tools (screwdrivers, pliers)

Parts Required:

• Spark plug (for cylinder 4)
• Ignition coil (if faulty)
• Fuel injector (if clogged or faulty)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical components.
• Allow the engine to cool before removing spark plugs or ignition coils to prevent burns.