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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaning kit.
• Gather necessary parts (see Parts Required section below).
• Disconnect the vehicle battery to ensure safety.

2. Replace Spark Plug and Ignition Coil

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the electrical connector from the ignition coil on cylinder 1.
  3. Remove the ignition coil using a socket set (usually a 10mm socket).
  4. Remove the spark plug using a spark plug socket and ratchet.
  5. Inspect the old spark plug for wear and replace it if necessary.
  6. Install the new spark plug and torque it to the manufacturer's specifications (typically around 22 lb-ft).
  7. Reinstall the ignition coil and reconnect the electrical connector.

3. Test Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Use a noid light to check for signal at the fuel injector connector; if no signal, further diagnose the wiring or ECM.
  3. If the signal is present, consider cleaning the fuel injector or replacing it if it's faulty.
  4. Reconnect the fuel injector connector after service.

4. Perform Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for several seconds and record the compression reading.
  4. Compare the compression reading with the manufacturer's specifications (typically around 180 psi).
  5. If compression is low, further investigate potential causes (e.g., valve seals, head gasket).

5. Inspect for Vacuum Leaks

• Sub-steps:
  1. Visually inspect all hoses connected to the intake manifold.
  2. Use a smoke tester to identify any vacuum leaks.
  3. Repair or replace any damaged hoses or gaskets found during inspection.