^infantrytroop22, as answered already, removing the exhaust hangers have no effect. However, I can imagine if someone go crazy tightening the 2 nuts on the exhaust hanger or if the threads on the nuts are not smooth, they can run the risk of loosening the bolts because the direction on tightening the exhaust hanger nuts is the same direction as loosening the bolts. So what I would do if I remove the hanger nuts is to make a mark on the bolt side and make sure they didn't move after you put the exhaust hangers back on. Can never be too careful, right?
^chriszeh, not sure if that was a joke or not, but I have to remove the exhaust and the heat shield to get a torque wrench in there. I am not sure how othe folks get a torque wrench in there to check that they are at the right torque. There aren't much space in there to put a torque wrench to check 100 NM.