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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Allow the engine to cool before proceeding.

2. Replace Spark Plug and Ignition Coil

1. Remove the engine cover (if applicable) using a socket set.
2. Disconnect the electrical connector from the ignition coil.
3. Remove the ignition coil by unscrewing it from the cylinder head.
4. Take out the spark plug from cylinder 3 using a spark plug socket.
5. Inspect the old spark plug for wear; replace it if necessary.
6. Install the new spark plug to the manufacturer’s specified torque (typically around 15 lb-ft).
7. Reinstall the ignition coil and secure it in place, reconnecting the electrical connector.

3. Inspect and Repair Fuel Injector

1. Disconnect the fuel injector connector for cylinder 3.
2. Remove the fuel rail (if necessary) to access the injector.
3. Replace the fuel injector if it is found to be faulty or clogged.
4. Reinstall the fuel rail and ensure all connections are secure.

4. Conduct Compression Test (if necessary)

1. Remove the spark plug from cylinder 3.
2. Insert a compression gauge into the spark plug socket.
3. Crank the engine to obtain a compression reading; compare it against manufacturer specifications (usually around 150-200 psi).
4. If the reading is low, consider further investigation into piston rings or valves.