EGR and DPFE Thanks!
This is a general thanks to all who have shared knowledge on how to replace the DPFE sensor and clean the EGR valve system. I followed the advice found in several threads, and now have a happily running truck. I even landed 20.9 mpg highway today with the AC running and NO CHECK ENGINE LIGHT!
It was a quick and easy job, even for a non-mechanic like myself thanks to all the good advice here. You all are great.