I just installed a obx intake manifold, a jeep 60mm throttle body, and a obx fuel rail on my 420a turbo. The problem is when i reach around 5 to 6 pounds of boost my car will start to sputter, not allowing me to reach any more boost. My car ran fine till after the mods. I have a missing link hooked up to a 6inch vacuum hose runnig to the intake manifold. I have no idea what i could be , need help???

You have a missing link hooked up to a vacuum hose? The ML should be mounted between the MAP sensor and the intake manifold. The hole should have a cotton filter in it (depending on the model), which is vented to the atmosphere.

Th map sensors is mounted to the missing link but the missing link is runnin to a 6 inch hose that then runs to the intake manifold, My mainfold never had the holes for the missing link, thats why i just ran a vacuum line to it.