Well, every once in a while around 30-35 mph when I go WOT, the car doesnt go past 3000 rpms, it only does this about 1/10 times, but still I dont like it. I know my 02 sensor on my passenger side behind the cat is bad. Is that the cause of the problem or is there possibly a bigger problem at hand?

 

It is unlikely that an O2 sensor is going to cause the engine at random to fail to operate beyond 3,000rpm. Particularly an after-cat sensor, whose only function is to indicate whether the cats are working or not.

I think you might have better luck asking this on LS1 Tech, where it belongs. Moving it there......

 

sounds more like a bad fuel pump to me.