SLPZ28

I have all the basic bolt ons with PCM tunning and so on plus a comp cam 224/228 with a 581/589 lift on a 112 LSA. Now I had a loudmouth cat-back and changed over to a spintech 3inch cat-back and did away with my cats also. Now the problem is my Headers and y=pipe are shaking like crazy? They never did that before? is it due to removing the cats and flowing more exhaust? I don't see that any bolts are lose? Anyway I also was woundering will my PCM lean out the car some because the gas smell is bad if not I'll have that fixed as well? Thanks Dan