Need help - bad cats?

i keep hearing a screech sound coming from the exhaust, or a rattle in the muffler or cat.
i also down shifted and heard a screeching sound, i am clueless. maybe some taco expert can help.

 

screech could be a messed up baffle but other than that i dont really know. id like to say something intelligent about the tranny but then i would be telling you a lie hopefully someone knowledgable can chime in

 

i dont feel it but i hear it it sounds like its coming from the back. no it does really effect the truck.
i was dropping my gf off at school and i have go down a steep hill ass hill, but as i was goin down someone pulled out in front of me so i went down to 1st and heard a nasty noise. and i was going fast at all

 

if its coming from the back i would check the diff. idk if that would cause the weird shifting behavior though

 

Grease your drive shaft lately? I had a screeching sound from the back, thought it was the brakes but It turns out that my drive shaft was dry.

 

sooo i looked under my truck and my exhaust mount is broke, so maybe thats it. im gunna get it weld back up and see if it helps.
i kinda have a feeling its the tranny tho =/ in the morning it takes a while to shift through gears.

 

yeah i had that issue with a u-joint, but i need to greasy my drive shaft.