how to diagnose P0301 misfire code on Volkswagen Golf MK7 (2015-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.
• Allow the engine to cool down if recently operated.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Unscrew the holding bolt using a socket set.
  • Gently pull the coil out of the spark plug well.
• Remove the old spark plug:
  • Use a spark plug socket and ratchet to unscrew the spark plug.
  • Inspect the old spark plug for wear or fouling before discarding.
• Install the new spark plug:
  • Apply a small amount of anti-seize compound to the threads (if applicable).
  • Torque the new spark plug to the manufacturer’s specifications (typically 22 lb-ft for VW).

3. Replace Ignition Coil

• If the coil is faulty, replace it:
  • Install the new ignition coil in place of the old one.
  • Secure it with the holding bolt and reconnect the electrical connector.

4. Fuel Injector Inspection (if necessary)

• If the misfire persists, test the fuel injector:
  • Remove the fuel injector from cylinder 1 using appropriate fuel line tools.
  • Inspect for clogs or debris.
  • Replace with a new injector if necessary, ensuring proper seating and connection.

5. Reconnect Battery and Test

• Reconnect the negative terminal of the battery.
• Start the engine and allow it to reach operating temperature.
• Monitor for any check engine light reactivation or misfire symptoms.