2000 Mitsubishi Galant OBD2 codes P0170 and P0125

My 2000 Mitsubishi gallant is having a lot of problems. Its making a loud noise, has trouble when accelerating, stutters on highway and sometimes idles at stops. The Air conditioning doesn't blow hard at all and it makes a louder noise when on. Whenever I start my car My radio/cd player wont play, no matter what I do(turning it off/0n, adjusting volume or switching stations) it still does nothing, anywhere from 5-45 minutes later it starts blasting music out of no where and then will randomly cut in and out.

I took it to O'reillys to test it and It came back with OBD2 codes P0170 and P0125.
What all is most likely wrong with my car?
What could be the cause?
What should I check for, what steps do I take?
What would be the cost for repairs or parts?

Thanks Bree