I dont really know how to explain it, so I'll start from the begining. I have done a few mods, filter, downpipe, and a 40 horse Banks Chip. Truck was running fine, but started to notice a slight vibration and wasnt quite sure what was causing it. After about three weeks, I tore the front end apart found a rough bearing and a few loose ball joints. I thought I had found the source and for the most part I did so I replaced everthing. But when cruising about 60 if I eased into the throttle I could feel a mild vibration in the throttle pedal so I'm thinking the engine isnt quite up to snuff. It had been dieing every once in a while and the wait to start light comes on, but I figured out one day if I tapped on the kickpanel with my foot it would do it every time so I knew I had a loose connection in the ECM. I have been wanting a tuner instead of a chip so i bought a SuperChips Micro, tore out the ECM one day took out the chip, and installed the tuner. Truck hasnt died once since then, but the vibration is still there. But what really makes me think something is wrong is when I change stages it doesnt really make much difference. Even on the high setting it still doesnt give a hint of black smoke out the pipe and almost seems to run worse. It still runs decent but not like I thought it would. I dont think I'm getting enough fuel so i just put a fuel pressure guage on it but when its idling the guage just goes nuts and fluctuates very, very, fast from about 5 to 70 psi but don't know if thats normal or not. Pulled the codes and all I got was a EBV code. Got to got back to work tonight so I cant tinker with it anymore, thought I would ask you guys for advice before I leave.

 

If you have a standard with the dual mass flywheel that could be your problem. They are prone to failing and cause all kinds of vibrations. Or you could have a U joint on the way out. If any of them have red dust on them, change them. Or even the carrier bearing could be failing. Those are the most common vibration causers I know of. Hope that helps.