I have seen the crank case filter in magazines and it seems like a cheap mod. BUT does it do anything. Where does the hose from the passenger side valvle cover go to? do you just take it out and put the filter in. Will this effect a chip? Is it better for your engine.

 

Don't that hose go back to the intake for reburn? I can't see it helping personally.

 

A crankcase breather is on all vehicles from about 1970 on. It draws vapor from the crankcase usually thru the valve in the passenger side valve cover, back into the air cleaner to reburn any vapors.

Does it help? Since it cause poor performance with it's pluged, I would hazard a guess that it does.