p0332 knock sensor

I have a 2001 gmc sierra 4x4 with the 5.3L engine and my engine light has come on. The code that is being returned to me is p0332, the knock sensor 2 circut low imput circut(bank 2). Where abouts do I find this sensor? And is it easy to change. I have some experience with working on my vehicles but not that much. I also have another question. When I am at normal road speed(50-60kms) and I go over a bump in the road, it feels as if my back end is hopping or skipping all over the road and that I may loose control. I have checked my shocks,springs and u joints and they all seem to be alright. Any ideas what may be causing this? I should add that it seems alright when I have the back loaded down.

I have an '01 GMC Sierra also with the same (knock sensor) problem. I have called the dealer and them claim that the knock sensor is under the intake manifold. This requires alot of work. I also believe that they told me that there were two knock sensors under the intake, so you should go ahead and replace both of them if you are already in there. As far as your bouncing rear end, it sounds like shocks more than anything else, but I'm not 100% sure.