1997 Ford Explorer code P0401

How do I replace the EGR valve located at the back of the engine near the firewall? Does the intake maniflod need to be pulled? The manual only shows a v-6 and I have spent the better part of the day w/my brother-in-law on the web triing to find a motor that looks like it. The book said there should be a DPFE sensor - cant find it on this motor! Also that it may infact be the PFE system. One site suggested replaceing the EGR valve tube (with a flex tube)located by the oil filler tube on the manifold but it was not there either. I am so flustrated w/this vehicle I could cry. It also needs front wheel brgs to pass inspection (last month) We've already put in rotors, brks, tie rods and tortion bar bushings. Please help me out if you can I'm ready to drive it in the river.