Air without fuel doesn't add power on its own. Hence you aren't really seeing much in the way of a performance change. I'm not sure what stock boost was on the 1Z but I'm pretty sure it was in the low teens. Sounds like something still isn't right or you have a tune on the ECU already. There is a short piece of hose inside the ECU itself that goes from the port on the case to the actual sensor, it is VERY common for that to split and leak. Might be with checking out, you should be able to tell if you have a tune at the same time as the chips are usually marked. Sent from my XT1097 using Tapatalk
Adding a boost controller is a step in the wrong direction in my opinion. You have something wrong somewhere... It's not uncommon for the wastegate to stick - have you checked that out? Sent from my XT1097 using Tapatalk
You can pop the rod off the arm on the turbo and move the arm by hand. It should have near zero resistance. You may also have oil pooled in your wastegate effecting things. If you have compressed air and a regulator you can try applying 5 or so psi to the wastegate directly and noting it's movement. I forget the exact amount of pressure the wastegate normally sees in this system. You should probably check those numbers and then test accordingly.