Intermittent surge?

[jsbihn]

Hey all,
I have this intermittent surge or miss or something.
Basically what it is doing is every now and then, depending on the gear or the rpms, the truck will feel like it is being held back then it feels fine... or it will show on the tach the rpms going up and down a couple of times (usually its goes up or down ~200-300 rpm). It doesnt always do it, and it doesnt always show issues on the tach... ie. the being held back feeling is usually when I am driving or maybe accelerating.

Not sure what is going on. If it is trans related, fuel related, maf related, ignition related, or whatever
Given I dont have any CELs and even when I use my ELM code scanner nothing is picked up... which I know doesnt mean much, but still no CELs.

So just wondering what you guys think it is.... so I dont have to completely rip apart the rig trying to find it.

Thanks