1991 silverado 5.7 idle problem

Truck gives egr system failure code, replaced egr and egr selenoid and truck still running bad. When starting the truck it usually dies fast, rough idle like its skipping and seems to run fine when accelerator is pressed. motor recently rebuilt. Any help would be appreciated.
SAMSUNG-SGH-A707/1.0 SHP/VPP/R5 NetFront/3.3 SMM-MMS/1.2.0 profile/MIDP-2.0 configuration/CLDC-1.1 UP.Link/6.3.1.20.0