LS1PowerWS6

I am having nearly the same issue with mine. Just installed Pacesetter LTs, a Borla and removed the cats yesterday and the hotter it gets the more choppy and sluggish it gets. Prodominantly in the lower RPM range. Although my front O2s have been hooked up at the collector but no rear O2s. The rear O2s play just a big a part as the front I'm assuming? Was going to plug in the live O2s back into the Y because I was told it would run better even with 2 sets of live O2s in it with no cats. Will this be the case or are simulators the only good solution aside from having it retuned to delete the rear O2s altogether? And will the simulators make it unneccessary to tune and delete the rear O2s?