Exhaust and 2 minor problems.

Ok. First things first. Hopefully ordering IMCO Extreme axle backs today. This may be a dumb question, but I know how sensitive our computers are, I shouldn't need a tune for this should I? Second question, when my AC is on I can hear what sounds almost like a purge coming from the passenger side floorboard. It's a puff, sounds like air or something and happens for a split second every minute or two - got to be from AC because it only does it when it's on. AND third, my driver side, side mirror housing is aparently loose. It rattles when I shut the door and I can shift it and it will pop, anyone know yet how to tighten those up?

Thanks in advance.