how to fix the engine misfire in Volkswagen Golf MK7.5 (2020-Present) with P0300 code?

Solution

1. Preparation

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

2. Replace Faulty Ignition Components

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Disconnect the electrical connectors from each ignition coil.
  3. Remove the ignition coils by unscrewing the bolts and gently pulling them out.
  4. Inspect the spark plugs; if they are worn or damaged, remove them using a spark plug socket.
  5. Replace the spark plugs with new ones, ensuring they are gapped according to manufacturer specifications.
  6. Install new ignition coils and reconnect the electrical connectors.
  7. Reinstall the engine cover.

3. Inspect and Clean Fuel Injectors

• Sub-steps:
  1. Depressurize the fuel system by removing the fuel pump relay and starting the engine until it stalls.
  2. Remove the fuel rail by unscrewing the mounting bolts.
  3. Carefully detach the fuel injectors from the fuel rail.
  4. Clean the injectors using a specialized fuel injector cleaner or replace them if necessary.
  5. Reinstall the injectors onto the fuel rail and secure it back onto the engine.

4. Check for Vacuum Leaks

• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to detect leaks around the intake manifold.
  3. Repair or replace any damaged hoses or seals.

5. Reassemble and Test

• Sub-steps:
  1. Reconnect the battery and ensure all tools are removed from the engine bay.
  2. Start the engine and let it idle to check for smooth operation.
  3. Monitor the vehicle with an OBD-II scanner to ensure there are no new codes and that the P0300 code has cleared.