What are the two rubber pieces near the converter on both sides on a 89 Buick LeSabre?

I looked under my car where the catylic converter is,on the left and right side there is a thick rubberlike o'ring that holds the converter up,I also noticed that there are little cracks in the o'rings and I wonder do they need to be changed.Also,I can push up on the the bracket which connects the pipe to the converter and when i do that,it makes the sound of the car much better.Do I have a serious or minor problem here?