I have a 99 si with the b16a2, it has a CAI thats it so far, there is a funny noise comin from the transmission. i've been told it was either the throwout bearing or the imput shaft. It only sounds when my foot is off the clutch...i dont know if it only sounds like that when its not in gear but i cant tell cuz the car is driving the rest of the time it sounds kind of like a rattle...but a very very very fast rattle.......please help

 

sounds like TO bearing.

 

how hard is that to replace myself? or should i have aamco or a transmission specialist do it? is there a possiblity that it is the input shaft? and way to tell