Only when decelerating does it rattle. Sounds like something is falling off. Accelerates fine, idles fine, and when I push on brake while slowing down the noise stops. As soon as I slow down even the smallest bit in any gear it happens though . No idea what could be wrong.

 

Do you have an aftermarket exhaust? I've seen some cars with aftermarket exhausts that cause quite a bit of resonating rattle when decelerating.

 

Figured it out. Yes I do have an aftermarket exhaust but Apparently my front driver wheel was coming loose. Either it was a failed attempt t steal my rims cuz a key is needed for every lug or it have hit so many potholes my lugs were loose.

 

Glad you figured it out. Hopefully it doesn't involve attempted thievery...