thats a heat shield thing and your muffler, your cat should be right under the cab.

 

ya i realized i posted the wrong picture. my cat shoukd be in front of that and its clogged so its gotta go. and i tried the wd40 on the p/s pump pulley and nothings changed so idk. ill try the pry bar and more penetrating oil later

 

could i distinguish if it was the ac/idler puley by turning the ac on and off while listening for a change in sound? id just do it but im about 60 miles from my truck

 

only if its really bad lol.