yes sounds like a vaccum leak as far as the idle problem, but i have also seen them have erratic idle when the egr is getting the wrong signal.i'm pretty sure the egr shouldn't be getting any vaccum at idle, and that happened to me because my vaccum source to the egr came from a vaccum control temp switch, and it was bad allowing vaccum to the egr holding it open at idle. good luck

 

What about the timing chain? Could it have slipped at 154,000 miles and everything else is red herring?

 

I'll have it all back together today. I found a broken wire and a cracked vacumm fitting at a ported vacumm switch. I'll know more later.I hope it's not the timing chain, but I'll be checking that as well.

Thanks for the suggestions everyone.

 

 

WOO HOOO!!!!!

I finally have the truck running good. I'm not sure what the exact problem was or if it was a combo of things.

For anyone having the same trouble heres a list of what I replaced...

EGR valve, EGR position sensor,EGR tube to manifold, all upper motor gaskets, all vacuum lines and fittings at the ported switch bank(rear drivers side valve cover,by coil),replaced intermediate plug at first ported switch,repaired some exposed wires in same location, Put factory wires,plugs, cap and rotor on.

I also cleaned the throttle body, upper intake and IAC valve.
I hope someone can put some of the info I found to good use.

Thanks to ALL who replied and put me on the right track.

PS... No oil leaks... Woo Hoo!!!!