1994 Cavi... knocking noise when decelerating
 

Hello all. So I have a 94 4 door wagon, and I am hearing a distinctive knocking noise when I let off the gas. It goes away if I hit the gas or if I put on the brakes. However, if I take the car out of gear and coast in neutral the knocking noise continues with the brakes applied. Any ideas of where to look or what it might be?