air catch can for idle

[thekawaii]

I tried to figure out why my car can't stay up 800 rpm whenever rpm drops fast.I figured some of after market turbo cars has small air catch can between air intake hose and idle air hose.

I didn't tried that one yet but anybody has experience with air catch can? what does it do exactly?

[Chezedik]

Why wouldn't you just hook up the IACV on a breather filter so that it would be clean air, but at atmospheric pressure. Since at idle you have manifold vacuum, the valve would be free to control the idle. Oh, and be sure to clean it.