Yesterday morning on my drive to work I had an unexplained loud noise that sounded like I had run over a tricycle. I was driving about 50mph and the road was completely clear. It drove fine the rest of the way to work, but, on my way home(20mi) when I would stop it would struggle to idle and hesitate on acceleration.

When I heard the noise seemed to start in the middle of the car just behind me and continue to the wagon's cargo area. On visual inspection nothing seems out of place but the rear muffler now vibrates and looks to need a new hanger.

Any ideas.

My first thought was was my cat was self destructing.

Any ideas?

Thanks