how to fix P0303 misfire code in Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench.
• Remove the ignition coil cover if applicable.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear, fouling, or damage.
• Replace with a new spark plug, ensuring it meets OEM specifications (typically NGK or Bosch).
• Torque the spark plug to the manufacturer's specification (around 22 lb-ft).

3. Check and Replace Ignition Coil

• Tools Required: Socket set, multimeter.
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil from cylinder 3.
• Test the coil with a multimeter to check for proper resistance.
  • Primary resistance: 0.4 to 2 ohms.
  • Secondary resistance: 6,500 to 20,000 ohms.
• Replace the ignition coil if it is out of specification.
• Reinstall the new coil, ensuring it seats properly over the spark plug.

4. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel line disconnect tool, fuel pressure gauge.
• Relieve fuel system pressure by removing the fuel pump relay and starting the engine until it stalls.
• Disconnect the fuel line from the fuel injector.
• Remove the electrical connector from the fuel injector.
• Take out the fuel injector from the cylinder head.
• Inspect the injector for clogs or damage.
• Replace with a new injector if necessary, ensuring it fits securely.

5. Reassemble Components

• Reinstall any removed components, such as the ignition coil cover and other engine covers.
• Reconnect the negative battery terminal.