EGR/PC leak?

I recently acquired a 1995 V6 5 speed Mustang. I've been trying to locate a funny sounding leak at the rear of the engine. At first, I thought it was a doughnut gasket. Then, I started looking for the EGR pipe to be leaking, but I can't find anything there yet. Then, I happened to take the PCV valve out of the right valve cover, and put my finger of the end of it, and the funny sounding leak goes away, or is greatly diminished. The line going to this PCV seems to go up under the back of the intake manifold. What does it connect to under there? Am I on the right track?

Thanks -
Steve