92 lancruiser exhaust noise

For 2 weeks the silver cannister below the driver side door rattled with each acceleration and it appeared that the mounts on it had rusted loose. Now the rattling has ceased, but there is very loud exhaust noise. and strong exhaust odor, every time I accelerate.
What is this metal cannister, what does it do, and what does repair entail? Thanks

It sounds to me like your muffler or catalytic converter has fallen off. You should fix it asap. With winter coming on, you are likely to asphyxiate yourself with the windows closed. A muffler shop can tell you what you need.