I am trying to figure out what is going on with my car. I have the hallman manual boost controller and it has been working great holding 25psi with some drop by redline for the past 6 months, a few days ago the car felt slower and like the turbo was not spooling as fast as normal so I got a data log and saw it was only getting 17 psi so I did the following tests...

Turned the boost controller all the way down and got 10 psi

Hooked the wastegate up to a vacuum source without the boost controller got 10 psi

Turned the boost controller all the way up and got 17

Unplugged the wastegate and got 17psi

Boost leak test and did not find anything

Swapped bov's and same thing

Last thing it could be is the wastegate right or what are the symptoms of a turbo that is going bad?

Oh yeah stock evo 9 turbo and wg

 

You need to establish whether or not your WG is functioning properly. Disconnect and plug the lines to the MBC. Run a length of vacuum hose directly from the compressor housing discharge nipple to your WGA. Now, raise boost by turning the turnbuckle inward. This way you'll find out if your WGA is functioning properly or not. If boost increases and holds...then the actuator is OK.