If the vanes are "stuck" then you can usually tell by monitoring the truck.* VGT duty cycle will either be stuck at .15 or .85
Here is another test to see if your vanes are cycling.* This a simple test, just plug and unplug the vgt solenoid while the truck is idling.* You should easily hear the vanes cycle and exhaust note change.* If you hear no change (assuming all your sensors are working properly) then we can try to work the air out of the system.* Repeat this process a few times, unplug and plug the solenoid back in.* THEN tap on the vgt solenoid with a hammer (the metal part that sticks out of the front of the turbo through the bracket, NOT the plastic clip), *then tap on the back of the turbo where the vgt cavity is (see picture below where the red arrow is pointing).* Then unplug and plug the vgt solenoid back in.* Do this 4 or 5 times to see if it gets the vanes cycling.* EVEN WHEN the vanes start to cycle you can continue the process a few more times to get the air worked out of the system.
After you get the vanes cycling I would RELOAD the same tune.* That way it resets the KAM and it will re learn the vane position and shifitng points.* I would then do a trans relearn which will also help with a turbo relearn.
Set the truck back to stock (unload the tune).
Unplug the batteries and let it sit for an hour
Touch the positive to negative cables a few times to make sure all the power is drained.
Plug the batteries back in and load the tune
Spend a minute sitting there idling and moving the shift lever from P to R to N to D to N to R to P etc.
Then go for a drive.* Take it easy and stay under 1/4 throttle for about 10 minutes.* Make sure it is stop and go driving so the tranny can shift through the gears.
After about 10 minutes the do a couple of 1/2 thorttle runs.* Then do a couple 3/4 throttle runs.* Then finally do a couple of WOT runs.
After that I would suggest double checking for boost/exhaust leaks.* Even brand new parts can get misaligned and leak.
Exhaust leaks are a big problem.* Bigger turbos will usually make leaks worse.* Check the ypipe bellows and the ypipe to turbo connection.* Those are very common.* An easy way to check it would be to have someone stick the truck in drive, hold the brake, and give it some gas.* Push the pedal as hard as you can without causing the truck to move.* Look for any smoke coming out from behind the turbo.* If you see any smoke then you need to find and fix the leak.* It is best to be running a race tune and just MASH the throttle, then when the tire are about to spin let off and try again.* You want to produce black smoke if possible because it is easier to see.
Watch this video to see how to check for exhaust leaks*
https://youtu.be/nOpO4gGS0vc
Watch this video to see how to fix common 6.0 exhaust leaks*
https://www.youtube.com/watch?v=lxvcg7piROI
Boost leaks are also a big problem.* The most common areas are the boots on the charge pipe, plastic ends on the intercooler, and the plastic hot side charge pipe on the drivers side.* If you have a plastic charge pipe on your drivers side then replace it ASAP.* They will not hold up under high boost.* We recommend pressurizing the intake to test for leaks.* Pressurize through the turbo inlet up to about 20-25psi and listen for leaks.* The best option is a boost leak detector from dieselsite.* Here is a link.
http://www.dieselsite.com/dieselsiteturboboostleakdetector-4.aspx
Pull and check all of the following sensors.* Use your programmer to make sure they are reading right.
BARO sensor is located under the dashboard.* Make sure it is plugged in and reading right.* The BARO reads barometric pressure.* Depending on your elevation it varies from 13.9-14.5 typically.
MAP sensor located on passenger side by the air box.* Make sure the tube going from the sensor to the motor is not cracked.* Make sure the tube and sensor are clean and not clogged up.* The MAP sensor should read the same as the BARO sensor with the key on engine off.* Then as you build boost it should go up with boost.* The boost sensor actually reads off of the MAP sensor, but it subtracts BARO to get boost.* So (MAP - BARO = Boost).**
MAF sensor is located between the air filter and turbo.* Make sure it is clean and plugged in.* It should read zero #/min with the key on engine off and it should go up as you accelerate.* Make sure it is not stuck on any certain number
EBP sensor is located off the exhaust manifold on the drivers side.* There is a tube going from the exhaust manifold to the sensor.* It is very common to clog and have issues.* Clean out the tube and make sure the sensor is not clogged.* EBP should read 0psi with the key on engine off.* Then it will go up with boost.* EBP will always be 5-15psi higher than boost when acceleration.* There is no set number for EBP, just make sure it is not stuck on any certain number.* NOTE:* SCT devices will not read EBP psi correctly... but you can still uses it to figure out your issue.45-50psi on your SCT is really 0-1psi100-120psi on your sct is really 10-15psi170-180psi is really 37-40psi
IAT sensor is connected to the top of the intake manifold near the fuel bowl.* Pull it out and make sure it is clean.* It is very common to get covered in crap.* Clean it and make sure it is connected right.
VGT solenoid.* The vgt wire/pigtail are very common to have cracks, slices, and breaks in it, especially right where it plugs into the solenoid.* Double check everything to make sure it is working right.* An easy way to check and see if it is working right is while the truck is running. plug and unplug the sensor.* You should be able to hear the exhaust sound changing when you do that.* Your VGT duty cycle is only reading "desired vgt"* NOT actual!!!... that that is only reading what the computer is requesting.* .14 is all the way open and .85 is all the way closed.* It should never be stuck on any number.* (but a stuck number does not always mean stuck vanes, for example if you vanes are all the way open (rumble at idle) and the vgt duty cycle is stuck at .14... then the vanes are not stuck, the computer is commanding the vanes open because there is another sensor not reading right and the computer is trying to compensate for that.
These don't relate directly to boost but it is still a good thing to check.* They can really hurt performance.
ICP sensor
IPR
FICM (make sure voltage is good)
YouTube boost leak video
https://www.youtube.com/watch?v=flV24cxn1vY&t=2s