Hey
Sorry I dont really have a solution to your problem but I thought id let you know your not the only one. I have a B16a1 im not sure if I have two O2 sensors also but it does the same thing when I hit a certain throttle percentage. When I put my foot on the gas about 2/3 of the way down my car starts to hesitate a little. So I pretty much have to either floor it or go a constant speed. I cant gradually accelerate. I think its probably a dirty fuel filter or dirty/clogged fuel injectors but i havnt gotten a chance to check/change them.

Hope someone has some sort of insight to this.

Mike.