Yeah I used to run the stock T3 turbo at around 15-17psi. Although it killed the turbo and really doesnt do anything but move a bunch of hot air passed 15psi. (this was with MS&S, Front mount IC and 440CC injectors). It sounds like you either have something hooked up wrong on the boost controller or maybe your gain is up too high. I would double check the installation as well as go over all the settings. Do not run anything over 12psi on your stock ECU/injectors and fuel pump. Do you have a wideband on that gauge as well? If not.. I really suggest getting one so you know what your looking at there as far as A/F..