97 chevy 5.7. I have 3 code that the reader picked up. P0141 P0300 P1133
 

Can someone tell me why both o2 sensors would go at the same time?

I'd be willing to bet you have a vacuum leak that is triggering both 02 sensors. with the truck running spray brake cleaner near all your vacuum hoses.

I had a P0141 on my truck two weeks ago and then realized that my dumb ass forgot to tighten down the clamp on the intake right after the MAF...