Personally i respectfully disagree with you. Since the ECU remap the kick in the lower rev range is definitely noticeable, maybe its just a coincidence that there is a noticeable improvement on my bike in the area where the exup operates, although i think not. I have the benefit of riding the FZ before and after the remap with the exup in operation on both counts. I'll be keeping my cables attached. I don't wish to start yet another debate on the exup as its been done to death over the years, i just want the OP to be aware of the different experiences we've, with my personal advice being to retain the exup and if possible, get the ECU remap.
If you remove the cat from the downpipes would this not have more effect on back pressure than removing the exup?The exup is open or partially open in most of the rev range but the cat is like a honeycomb that has quite small holes in.