how to diagnose a misfire in my Volkswagen Golf MK7 (2015-2019) with code P0301?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Remove the ignition coil harness from the ignition coil.
• Unbolt and remove the ignition coil from cylinder 1.
• Remove the old spark plug using a spark plug socket.
• Check the gap on the new spark plug (set to manufacturer specifications).
• Install the new spark plug and torque it to the manufacturer’s specified value (usually around 20-30 Nm).
• Reinstall the ignition coil and reconnect the harness.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil was found faulty during diagnostics, replace it:
  • Remove the old ignition coil as described above.
  • Install the new ignition coil and ensure it is seated properly.
  • Reconnect the electrical connector to the ignition coil.

4. Inspect and Replace Fuel Injector (if necessary)

• If the fuel injector was found faulty during diagnostics:
  • Disconnect the fuel injector harness.
  • Remove the fuel rail bolts and carefully pull the fuel rail with the injector off the intake manifold.
  • Replace the faulty fuel injector with a new one.
  • Reinstall the fuel rail and reconnect the harness.