ok newbie here again. THis time i have a prob with my turbo xs manual boost controller(not the dual stage, its the old one). This piece is leaking when i hit full boost and comming back down from 19 back to like 10 psi. It just started doing this. I am even wondering if its even the boost controller. but i figured it was since it is hissing from the little black o rings. it really loses boost and makes a loud hissing noise when it is taken over 5,000 rpm. any advice would be sweet.

 

Check your connections to the boost controller.. but if its going all the way down to 10 psi, it means its leaking all the way down since the wastegate actuator operates at 10 psi.. I had this happen on one occasion though I'm using a hallman which is constructed differently which means its not leaking.. What I discovered is the vacuum line from my blowoff valve had began leaking (in my case it split) and the DV (BOV) was where the boost was leaking out..

If you do a search there should be several other tidbits of information to help guide you.. Easiest solution is to replace it with a hallman boost controller..