Wierd Noise...

[AccordAddict]

OK when my car warms up and reaches the required tem and rmp the car starts to rev itself up and then fall down and rev back up and down continuously till i put it in drive or something. anyways i popped the hood when it was doing this and i heard a weird sound coming from a black cylindrical box on the top right side of the engine with a vacuum line hooked to it. it was making a wierd sound like sort of the sound a frog makes when its like "ribbit, ribbit" and it makes that sound when the car is reving, does anyone know what this box is and could this be causing the problem that my car has when it revs up and down? help plz, thanks.

[SHURIK]

vacume leak wich box is making noises what kinda engine u got tell me that and i will tell u what is up but i am prety shure u just have a vacum leak fix the leak and u should change ur pcv valve and ur egr and all the stuff will runn fine and smoth and like new and u will pick up on ur gas milege

[AccordAddict]

a20a3 engine i dunno what the box is called i dont have a shop manual in front of me, but its a black cylindrical box in the top right side of my engine.

[Hondacrazy]

There is vaccum lines in the box. And if it isn't it. It could be caused by your air mixture screw.