how to fix P0304 misfire code in Volkswagen Golf MK7 (2015-2019)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to prevent electrical shock.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil cover if applicable.
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil from cylinder 4.
• Use a spark plug socket to remove the spark plug from cylinder 4.
• Inspect the old spark plug for wear; replace with a new spark plug, ensuring it is gapped correctly (typically 0.028-0.032 inches for the Golf MK7).
• Torque the new spark plug to 22 lb-ft (30 Nm).

3. Replace Ignition Coil

• Tools Required: Socket set
• If the ignition coil appears damaged or has been replaced, install a new ignition coil.
• Reinstall the ignition coil by pressing it firmly into the spark plug and connecting the electrical connector.
• Ensure it is seated properly.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaning kit (if necessary)
• Remove the fuel injector from cylinder 4 if found faulty in diagnostics.
• Clean the injector using a fuel injector cleaning kit or replace it with a new one.
• Reinstall the fuel injector, ensuring O-rings are lubricated and seated properly.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Start the engine and let it idle for a few minutes.
• Use an OBD-II scanner to clear the P0304 code.