Air in fuel system.

[Chamberpains]

Is this code coming on when your driving or running the truck and the check engine light came on? Or did you just find it on the dash display as logged code?
You can often get this code logged from changing the fuel filters. It's just the nature of the beast when you change the filters and air gets in the lines.
But if your getting this going down the road or other times then you have a problem else where. Do you have a Davco filter on the truck? If so, run the truck and watch it to see if air is in the see thru bowel. Where do you hear the bubbles at?

Yes, your actuators could be shot. Rawze has posted on here, how to check them out. It's worth doing. Checking them will only cost you a gasket if the gaskets are not reusable. Replacing a bad fueling/metering actuator will be costly but worth it.

The lagging in power after the turbo replacement can be a couple things. The big one I can think of is air leaks on the CAC and piping. Loose clamp, cracked CAC, bad intake gasket, leaking sensor. Pressure test your entire engine and check for leaks. There are a couple posts on here about how to do that.