Alright, here's the deal. It's pretty much been doing this for the life of the car (46k miles) and it's now getting worse. I just shrugged it off before as just some engine noise.

When i throttle and start to take off, there's like a stream of continuous squeaking/squealing noise coming from the engine. It's much louder and noticeable when the A/C is running.

i know what a slipping belt sounds like and it doesn't sound like that at all. It has more of a "rattle" sound to it. It only happens while driving, not parked or neutral. It's faint without the A/C, louder with.

To me it sounds like a squeaky wheel or something going around and around, with a slight "tink tink tink tink tink" to it. Maybe a squeaky/warped pulley?

I'm not sure. That's why I need your help, or if anyone has heard of this before. I searched around and saw squeak with throttle cables but I dont think this is it.

If i have to, i'll drive around the neighborhood and try to "record" the sound.

My only engine "modifications" are a injen short ram CAI and ground wire kit.

 

Sounds like you are on the right track with the belts/pulleys. Does the xB have an idle pulley? Could be bearing in it gone bad. If it doesn't, could be a bearing in the alternator, a/c, etc.

If you haven't replaced the belts, now would be a good time. If you have, maybe there was too much tension and caused a failure.