how to fix persistent P0302 misfire code in Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the engine is cool before starting work.
• Disconnect the vehicle's battery to prevent electrical issues.

2. Replace Spark Plug and Ignition Coil

• Tools Required: Socket set, torque wrench, dielectric grease, spark plug socket.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector on cylinder 2.
  3. Unscrew the ignition coil using a socket wrench and remove it.
  4. Remove the spark plug using a spark plug socket. Inspect it for wear or damage.
  5. Install the new spark plug with the recommended torque (typically 22 lb-ft for most spark plugs).
  6. Apply dielectric grease to the ignition coil boot.
  7. Reinstall the ignition coil and reconnect the connector.

3. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaning kit (if cleaning), socket set.
• Sub-steps:
  1. Remove the fuel rail if necessary to access the fuel injector for cylinder 2.
  2. Disconnect the fuel injector connector.
  3. Remove the fuel injector using a socket wrench.
  4. Clean the injector using a fuel injector cleaning solution or replace it if it appears faulty.
  5. Reinstall the fuel injector and reconnect the electrical connector.

4. Perform Compression Test

• Tools Required: Compression tester.
• Sub-steps:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for a few seconds to get a reading.
  4. Compare the compression reading with manufacturer specifications (typically 150-200 psi).
  5. If compression is low, further investigation into the engine's internal components may be necessary.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Sub-steps:
  1. Inspect all vacuum lines connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine to detect any vacuum leaks or spray carburetor cleaner around the intake area to see if engine RPM changes.
  3. Repair any identified leaks.