my truck is an 04' cummins with the 305hp motor it has a rough idle thought it was the bullydog but i took it out and it still has a rough idle, feels like its about to fall apart any help is greatly appriciated

Thanks
Dallas  

what RPM is it at when it starts shaking? does it get any better when you rev it up? start by checking the motor mounts, tranny mounts, and the bell housing bolts. is the check engine light on? ive seen engines shake before because they had a dead cylinder.  

only when im idling at every other stop sign/ light ECT... i dont know what it is , i thought it was the bully dog i took that out returned it to stock and its still doing it . is it possible the bully dog damaged something, or threw a code and its getting a messed up signal somehow, it never did this before i threw the bully dog in it, it does smooth out when i accelerate, and some times when im stopped it idles totally normal.

Thanks
Dallas  

what rpm does it idle at?  

normally vibrations occur from something being worn out or unbalanced. but if it just the engine when it idles than that isnt possible. take it to a dealer and have them check for codes. it could just be an injector on its way out or with a bad spray pattern. check all the mounting bolts like i said before engines typically dont run as smooth at idle as they do at higher RPM, so if you have loose mounts it would make it noticable.  

it idles at 750, and my dad and i think the bully dog F'ed something up electronically, were going to undo the batteries for 15 minutes and see if that works IT DID NOT start doing this until i had that BULLYDOG  

Easy way to tell if you have a dead cylinder: use a Infrared heat gun. Point at exhaust port from Cyl head at each cyl before turbo. All temps should be within approx 50deg. One too hot is overfueling, one too cold is intermittant miss or dead cyl. The engine's firing order naturally will help smooth over an intermitant miss.  

I would take it to the dealer and reflash the ECM.
and have them check for codes.  

It was 3 injectors.  

How'd u figure that out? Did you take it to the dealer? Give us a little more here.  

Took it to a dealer and put it up to an injector kill test. They charged me $500 to let me know it was my injectors and wanted another $2500 on top of that to replace the 3. So I bought 3 injectors off of eBay and had my mechanic put them in there for free. in other words i saved $1700. I wont be going to the dodge dealership again.