how to resolve P0301 misfire code in a Volkswagen Golf MK7.5 (2020-Present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench, gapping tool.
• Remove the ignition coil on cylinder 1 by unscrewing the bolts and disconnecting the electrical connector.
• Remove the old spark plug using the spark plug socket.
• Inspect the old spark plug for wear and gap it to manufacturer specifications (0.028 - 0.032 inches).
• Install the new spark plug and torque it to the specified value (22 ft-lbs).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil (if necessary)

• If the spark plug replacement did not resolve the issue, test the ignition coil by swapping it with a functioning cylinder.
• If the misfire shifts to the other cylinder, replace the ignition coil with a new one.
• Tools Required: Ratchet and socket set.
• Reconnect the electrical connector and ensure it is secure.

4. Inspect and Replace Fuel Injector (if necessary)

• If the ignition coil is functioning correctly, check the fuel injector for cylinder 1.
• Use a noid light to check for proper electrical operation or a multimeter for resistance.
• If faulty, remove the fuel rail and replace the injector for cylinder 1.
• Tools Required: Fuel injector removal tool, ratchet and socket set, safety goggles.
• Reinstall the fuel rail and ensure all connections are tight.

5. Perform a Compression Test

• If the issue persists, conduct a compression test on cylinder 1.
• Remove the spark plug and insert a compression gauge.
• Crank the engine and record the compression reading; it should be within the manufacturer’s specified range (typically around 140-200 psi).
• If compression is low, further investigation into the engine's internal components may be necessary.