Noisy Exhaust

Just recently my van (1991 Plymouth Grand Voyager LE / 3.3 Liter engine with 245, 000 Kilometers) develop this very noisy rattling noise from down under.

I look at all the connections and nothing was broken . Everything is intact in the exhaust pipes and the cat converter.

The noise resembles that of a broken tail pipe that didn't go through the muffler to muffle the sound.

To teenagers, this would be wonderful as I know they like those monster sound off their pipes. But to a family guy, I wouldn't want it.

When I open the engine hood, there is a sound emmiting from it. Like water churning. Cannot pinpoint where because of the rattle the exhaust was making.

What could this be? If it was the engine about to give way, why would the exhaust pipes be emmiting this noise too?

Would it be the point where the exhaust pipes are connected to the engine? Haven't look in there but before I do, want to know a little bit more about where the cat converter and the pipe leading to the engine meets. and what kind of bolts or weld are they pieced together.

Please advise.

Much thanks

For all I know, it could just be the muffler that is probably broken in pieces inside.

Does anyone have any idea to throw here?

Did you find the solution, Im getting the same noise now