changed head gaskets..new plugs, wires, egr, DPFE..checked plugs, vacume connections, ect but no idea. It drives great..and in park it idles pretty good (some shudder at times) as well as neutral. But put it in gear and hold on! It studders so bad in gear at lights it confuses me..but again it drives well. I am wondering if maybe the valve cover or intake gasket is bad..I used all new of course but maybe one is bad (would a valve cover gasket do this..I know on bikes it will) so if no one has any ideas I recon I will have to yank off the upper/lower intake manifolds and valve covers and replace the gaskets...I am wondering if thats it? Hoping to GOD its not a head gaskets bad..that SUCKED doing. Any thoughts?