I can't boost lower than 14-15 PSI and I think my O2 sensor is out

[94talonawd]

Ok, well i was driving my car today and i just noticed that my O2 readings are not accurate anymore. When I am at idle, my O2 is at 5.00 Volts. When I am driving it around it jumps from 1 volt to 2 volt. I'm pretty sure my O2 sensor went out. Will this affect my car in any way?

My other question-
I cannot get my boost any lower than 14-15 psi. I dont know why. I made a custom boost controller. I am 100% sure that everything is hooked up right. Also, my Injector d/c is maxed out to 105%. I need to lower my boost! I have a 3/S fuel pump in my car, I was wondering if this was causing me to not boost any lower than 14-15 psi.

Well the mod list is on my signature. Can you guys tell me whats wrong? I've ran out of ideas.