truck is 2006 dodge ram with the 5.9L Cummins, service light came on, took truck to dealer and they said I had a bad injector- they replaced it then tell me that the service light will not go off because I need to replace all the injectors.. Pick truck up an its running rough , sluggish to get to speed and then the not ready to start light comes on. not sure what to do ?? the truck acted like it did not get fuel,when light cam on originally then I turned truck of and restated later and ran fine to get me home..

 

Depending on mileage it maybe time for injectors. You can try some hotshot striction eliminator

 

what kinda mileage are you looking at? fill out a sig so we know what mods you got. also, if you can do a cylinder cutout test that'll help to see if they are all on their way out.

 

321987 miles..

 

321987 miles.. No mods straight factory..

 

well i have seen them go out before that, so it could be time...

 

I had 3 injectors go bad so far in my truck (2007, 5.9CTD, 285k miles). Replaced them myself, not hard to do, just time consuming.
Did you do the ohm test for each injector, maybe more than one was bad?