my Volkswagen Golf MK7 (2015-2019) is showing a P0303 code what does that mean

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil for cylinder 3.
  • Disconnect the electrical connector.
  • Unscrew the bolts and lift the coil out.
• Remove the spark plug.
  • Use a spark plug socket to unscrew and remove the spark plug from cylinder 3.
• Inspect the spark plug for wear or damage.
• If worn, replace with a new spark plug, ensuring it matches OEM specifications.
• Torque the new spark plug to the manufacturer's specifications (typically around 20 Nm).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, inspect the ignition coil.
• Replace the ignition coil if it shows signs of damage (cracks, corrosion).
• Reinstall the ignition coil and connect the electrical connector securely.

4. Check Fuel Injector

• Use a multimeter to check the resistance of the fuel injector for cylinder 3.
• If the injector is faulty, replace it with a new one.
  • Disconnect the fuel injector connector.
  • Remove any retaining clips and pull out the injector.
  • Install the new injector and reconnect the electrical connector.

5. Verify Compression

• If misfire persists, perform a compression test on cylinder 3.
• Remove the spark plug and connect the compression gauge.
• Crank the engine and record the compression reading.
• Compare with specifications (usually around 120-150 psi); if low, inspect for internal engine issues.