how to fix P0303 code in Volkswagen Golf MK7 (2015-2019) misfire?

Solution

1. Preparation

• Gather tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench, ratchet, gap gauge
• Remove the engine cover if necessary.
• Unscrew the spark plug from cylinder 3 using a spark plug socket.
• Inspect the spark plug and clean the area around the spark plug hole.
• Check the spark plug gap; adjust if necessary or replace with a new spark plug set to the manufacturer’s specifications (typically around 0.028 inches for VW).
• Install the new spark plug and torque it to the manufacturer's specification (usually around 22 lb-ft).

3. Replace Ignition Coil

• Tools Required: Ratchet, socket set
• Disconnect the electrical connector from the ignition coil for cylinder 3.
• Remove the bolts holding the ignition coil in place and lift it out.
• Install the new ignition coil in the same position and secure it with bolts.
• Reconnect the electrical connector.

4. Check Fuel Injector

• Tools Required: Noid light or multimeter
• With the engine still off, disconnect the fuel injector connector for cylinder 3.
• Connect a noid light to the fuel injector connector to check for proper signal. If no light, investigate wiring or ECU issues.
• If the injector is faulty, replace it with a new one, ensuring proper seating and connection.

5. Reassemble and Finalize

• Reinstall any components removed during the process.
• Reconnect the battery.
• Clear the error codes using an OBD-II scanner.