i have an 05 g35 twin turbo with osiris tune im boosting 7psi, when i drive it boost right at times but then it doesn't boost at all. i have the greddy profecb2 boost controller and some people say it might be my boost controller or my waste gate not opening. any suggestions

 

If your waste gates are not opening you would have about 25 psi of boost, the waste gates bleed off boost when they open. I would remove the boost controller the waste gate springs should be 7psi anyway so the boost controller shouldn't be required? It is a place to start anyway.

 

do u know if its better to keep the piggy back or to have the osiris program

 

*Sigh*

Checking all your vacuum lines is a good place to start

 

What tuning solution works best depends alot on the tuner alot on the tuner!!! that would not be causing your boost issue either dont start throwing cash at stuff trying to fix the issue. Figure out or narrow down the issue first.