These are things you WANT to know when running higher boost and wanting to make good power.

Wideband 02 AFR
EGT's
Ignition timing advance
Intake temperatures

If you dont have the tools to monitor any or all of these, its in my best opinion to either save up for them, or dont run high boost until you do. Tuning off of the stock o2 sensor is just too inaccurate. Going from only several hundreths of a volt(eg .92-94)could mean running a 12:1 AFR, ro a a 13:1 AFR..its just not accurate enough in the rich range to give you a reading you can be confident on. EGT tuning can be tricky also. There are many other vaiables that can cause a high EGT other than running to lean..

Your best bet is to get on a dyno with a wideband, or fork over the cash for an incar wideband. Also, a pocketlogger or a laptop datalogger is a must have item also. After using my AEM wideband, i dont know how i ever tuned without it..I just used to tune to EGT pretty much, but that was never very accurate. If you want to be in the 13+ psi club, then get the mentioned tools to tune with, or do your tuning on a dyno. Don't forget to use your other "free" tools either, you EARS. Listening for the motor detonaing or misfiring, ect..sometimes can be the best tool ever :) Although you need to know what they sound like at the same time, for it to be of any use.