Does the truck have what feels like a miss?

 

Yes between 1100-1500 then it cleans up until about 2000-2100 then cleans up again. It feels like the cylinders are more balanced at certain rpms ranges. Only visible smoke is between 1100-1400ish.

 

Could it also be wiring to that bank or IDM?
May be worthwhile to do a volt/ohm check on the IDM and the 42 pin connectors.

 

It could be an injector flow imbalance. Too much readin' and replyin' lately, I don't remember if we discussed a chip/program in your truck.

It does this "chug" in neutral and in gear? What happens when you powerbrake? What happens when you keep it in 2nd gear and you take the speed up through the problem RPMs?

 

Truck is not chipped. The shudder/imbalance is subtle and does it in neutral, park or 1st and 2nd. Powerbrake seems to take a little of it away but not much. My wife can't even feel but I can. I am OCD about noises and vibrations/shudders I can't explain. As a helicopter pilot ALL unexplainable noises or vibrations are BAD and will be investigated!

Is there a link on how to ohm the IDM?

 

The closest I can get you is the UVCH link in my signature. If it's a subtle chug, you can verify you have one cylinder a bit "off" by checking the exhaust manifold temps on each port (laser thermometer). I've done this with my truck and found one cylinder that doesn't match its mirror on the other side. That's a work in progress.