Well...it allows your catalytic converter to work correctly.

And...it is illegal to remove it, regardless if you have emissions testing in your area or not.

So...because that is one of the few "rules" we have around here (discussing illegal activities) this discussion should be considered done.

I will say, it does not "steal" air from your engine and in the end, it does not really take much "power" to run as it usually only operates during start up and at WOT.

Good Luck,
Michael