SOmetimes my car will idle at like 3,500-4,000 RPM, thats when it idles, but sometimes it just stals, and will start back up, then stall. Sometimes it will be fine and wont do it at all, other times will do it the whole time im driving and i will have to keep it doing with the trottle, Is this perhaps the MAF Sensor? (mass air flow sensor)???

Please Help thansks.