how to troubleshoot a P0301 code in my Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, fuel injector cleaning kit, vacuum gauge.
• Disconnect the battery to prevent any electrical shorts during repairs.
• Allow the engine to cool down before working on any components.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1.
• Unscrew and remove the spark plug using a spark plug socket.
• Inspect the old spark plug; if it’s worn or damaged, replace it with a new spark plug that meets OEM specifications (typically NGK or Bosch).
• Torque the new spark plug to the manufacturer-recommended specification (usually around 20 Nm).
• Reinstall the ignition coil.

3. Test and Replace Ignition Coil (if necessary)

• If the spark plug replacement did not resolve the issue, swap the ignition coil from cylinder 1 with a known good ignition coil from another cylinder.
• Clear the P0301 code and take the vehicle for a test drive to see if the misfire follows the ignition coil. If it does, replace the faulty ignition coil.

4. Perform Compression Test (if necessary)

• Remove the spark plug from cylinder 1.
• Install the compression tester into the spark plug hole and crank the engine to record the compression reading.
• Compare the reading to manufacturer specifications (usually around 140-200 psi). If the compression is low, further diagnosis of the engine internals is required.

5. Inspect and Clean Fuel Injector (if necessary)

• If the ignition components and compression are fine, check the fuel injector for cylinder 1.
• Remove the fuel rail and injector assembly.
• Use a fuel injector cleaning kit to clean the injector. If the injector is faulty, replace it with a new unit.