When the car is on "p" or "n" the idle is arround 7-8. When it is on "d", "r" etc. it's about 4-5 RPM. This realy sucks, everytime I stop at a light I have to swicth to "n" in order to prevent the car from shaking and idle from going back and forth. Do you guys think its the Mass Air Sensor? The weird thing is the "check engine" light is NOT on!