how to fix P0301 misfire code on my Volkswagen Golf MK7.5 (2020-Present)?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, vacuum gauge.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before servicing.

2. Replace Spark Plug

1. Remove the engine cover if necessary.
2. Disconnect the ignition coil connector for cylinder 1.
3. Unbolt the ignition coil using the socket set and remove it from the spark plug.
4. Use a socket wrench to remove the old spark plug.
5. Inspect the new spark plug for proper gap (0.028-0.032 inches) and install it.
6. Reinstall the ignition coil and reconnect the electrical connector.
7. Repeat for all cylinders if necessary or if multiple misfires are present.

3. Inspect and Test Ignition Coil

1. Use a multimeter to check the ignition coil's primary and secondary resistance against factory specifications.
2. If the coil is faulty, replace it with a new one.
3. Reinstall the ignition coil and reconnect it.

4. Test Fuel Injector

1. Use a noid light or multimeter to check the injector pulse for cylinder 1 while cranking the engine.
2. If the injector is not functioning, replace it.
3. Reinstall the fuel injector and ensure all connections are secure.

5. Compression Test

1. Remove the spark plug from cylinder 1.
2. Insert the compression tester into the spark plug hole.
3. Crank the engine and record the compression reading.
4. Compare with specifications (usually around 150-200 psi) to determine if there are issues with the piston rings or valves.

6. Check for Vacuum Leaks

1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
2. Use a vacuum gauge to test the manifold pressure.
3. If any leaks are found, replace the affected hoses or components.