my Volkswagen Tiguan has a check engine light and code P0301, how to fix it?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Removal
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 1.
  3. Remove the ignition coil using a socket set.
  4. Unscrew the spark plug using a spark plug socket.
• Replacement
  1. Inspect the old spark plug; if worn or fouled, replace with a new spark plug (check manufacturer's specifications for the correct type and gap).
  2. Install the new spark plug and tighten it to the specified torque (typically around 20-30 Nm).
  3. Reinstall the ignition coil and reconnect the connector.

3. Check and Replace Ignition Coil (if necessary)

• Inspection
  1. Visually inspect the ignition coil for signs of wear, cracks, or damage.
• Replacement
  1. If defective, remove the ignition coil from cylinder 1.
  2. Install the new ignition coil and secure it.
  3. Reconnect the ignition coil connector.

4. Inspect and Replace Fuel Injector (if necessary)

• Inspection
  1. Use a multimeter to test the resistance of the fuel injector.
  2. If out of specification, replace the fuel injector.
• Replacement
  1. Disconnect the fuel injector connector.
  2. Remove the fuel rail (if applicable) to access the injector.
  3. Install the new fuel injector, ensuring a proper seal.
  4. Reconnect the fuel injector connector and reassemble the fuel rail.

5. Perform Compression Test (if necessary)

• Testing
  1. Remove the spark plug for cylinder 1.
  2. Insert the compression gauge into the spark plug hole.
  3. Crank the engine and record the pressure reading.
  4. If the reading is below the manufacturer’s specification, further investigation into engine internals may be required.