my GTI GOLF 4 IVE DONE EVERYTHING BUT ITS SHAKING AND ITS LIKE THE IS A PROBLEM WITH PLUG NO 3 DOSNT BRING THE SPARK . WHAT MY BE THE PROBLEM PLEASE ASSIST

P0303 VOLKSWAGEN - Cylinder 3 Misfire Detected...Possible causes; Faulty spark plug 3, Clogged or faulty fuel injector 3, Faulty ignition coil 3, Fuel injector 3 harness is open or shorted, Fuel injector 3 circuit poor electrical connection, Ignition coil 3 harness is open or shorted, Ignition coil 3 circuit poor electrical connection, Insufficient cylinder 3 compression, Incorrect fuel pressure, Intake air leak...The P0303 code means that the cylinder 3 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 3. If the problem persists more tests needs to be done to diagnose problem.

These are all good answers. Also: My Dad had a 2001 Golf with gas engine that showed a Check Engine light. The dealer replaced the ignition coil pack for a fee. Later we learned it was under recall for this so they got paid twice! So check with VW first.