Probaly been covered before. Ive noticed recently that my GP 1.9 M-Jet is stuttering/hesitating. Tends to be on slight throttle at just slightly below 2000rpm. Feels like its 'jumping' or running lumpy. Ive also noticed it sounds rattlier than normal and when idiling I can feel a bit more vibration than normal. Turbo sounds slightly nosier, its been replaced once. It feels slightly down on performance. I have run through wynns formula gold through a tank. Any ideas??