07 us SD. Recently fitted an itg filter and since then my idle has been running high. As much as 3k rpms.

So, started reading here, and I've done all the basics. Now it starts and idles fine at 1500 but slowly creeps to 2000 once it warms up.
I've:
-set tps. Tuneecu reads 0% to 93% wot. Voltages in spec
-thottle bodies are balanced
-multiple tunes tried. Reset done every time. Currently using akro smooth
-adjusted slack on throttle cable at the throttle body and on the handlebar.
-bgc is greased

What I've noticed is the throttle idles high if you don't have a hand on the throttle. But if you roll the throttle forward, it idles back down to 1500. So obviously my throttle isn't closing all the way. Again, there is proper tension on the return cable.

So, checked clearance between the butterfly and throttle body. Hands off, a piece of paper folded (2layers) can slide in-between. But, if I roll the throttle forward it tightens down so not even a single piece moves through. When you roll the throttle forward, you can see it close that last little bit.

And that brings me here. Obviously I've screwed up something and handled the throttle bodies too rough to get something out of spec. Is there an adjustment that can be made to get the butterfly fully closed? Some way to increase the spring tension on the return cable? It's not hitting any of the mechanical stops.

I'm at the point where I'm willing to try anything, because the next step is spending a large amount of money for a new set of throttle bodies.

Have you done the following:

1. Set throttle cables in tuneECU
2. Reset adaption in tuneECU
3. 15 min reset
4. Do a search for high idle - will give you more ideas to try