A while back, I noticed my PCM (silver part in front of the fuse box with a heat sink and 3 wires plugged into it) was loose. Like it's sitting in that slot, but I can wiggle it or lift it out with no resistance at all. Last week at the track I noticed it was the same on another Cobalt. I'm wondering if this is normal or is there a clamp or two missing that should be holding it firm in place?

 

It's normal. You could use zip ties probably if you're worried about it, but It's not going to move.

 

I noticed mine is the same too, I put that black hose that is above it down into the crack and that holds it steady.

 

I had that hose in there, but I wasn't sure if that could affect the hose or not, so I pulled it back out for now.