I didn't rewire my 255hp when I installed it, I don't want to. I'm probably running on the edge of too much fuel for my near stock beast as it is. At idle, there is a much more pronounced fuel smell to the exhaust than there used to be, I may be running rich down low. Even with my planned eventual 16g/550 setup, from what I've read I don't think a rewire would be necessary or even beneficial.