Mazda CX-9 Makes Squeeling Noise While Driving?

I own a 2009 Mazda CX-9 and up until a month ago it was working perfectly. It's been making a squeeling noise while driving, braking, and turning. When the state inspection test came along, it failed and needed a right tie iron replaced. The noise stopped for a few days, but soon returned. I've searched online, some saying it could be the power steering fluid/pump or a wheel bearing. At first th
e noise only occurred while driving, never when braking. Now, it makes the noise while driving, braking, and turning. The slower you drive, the louder it gets. I really need help finding what is making the noise before replacing something that has nothing to do with it.
I don't think it's the brakes, as when driving, the sound seems to come from the middle of the car, though sometimes it seems to come from the right side then the left side. I don't know what that means but, the brakes were replaced earlier this year.