As stated ..i would at least block off the egr.. get a finger stick to bypass the codes. Chances are if you dont block it off.. bypass it.. you may be "there" again.
07 Sierra Classic SLT,LBZ, EFI Live V2 DSP5 Tuned by Idaho Rob :rockin, EGR block off, PPE fuel shim kit, Ported fuel rail fitting, Amsoil BMK27 bypass filter.
PPE bleed screw, EDGE INSIGHT w Pyro..(Meyers Perf) ,Trans Go JR "Big Dipper", 4in MBRP SS CAT BACK,5IN SLASH TIP, XDI COLD AIR INTAKE,Drawtite Ultra Frame 20k ball, Westin SS steps,Bilsteins,Mag hi tech diff cover,Amsoil in all, Opti-Lube XDP ,Lund Stone deflector,sun .Sirius S50, Garmin GPS, Xtang Trifecta bed cver. DDM Tuning HID'S(all) 55w 5k brights, 35w 5k lo's, 35w 6k fogs. "All on Mod". ADP Nicktane filter adapter/cat fuel filter
Coming-Big Dipper Stage IV, pcv re route.
Other -Dakota 235in Alcohol Dragster 582bbc 7.01 @198mph
82 s10 388 SBC 10.01 133MPH