I've got a question sort of regarding this too. I put some 24lbers in over the summer along with a Pro-M maf to go with them cause they were pretty much free, and thought what the hell, couldn't hurt. I also have a 190 lph fuel pump which I only put in there if I ever did upgrade my car when the stock one went bad. From everything I've read, my fuel pressure should be the same, and it is (have a fuel pressure guage on there), but it seems to run really rich. Does the upgraded fuel system have to do with this, and if so, would an adjustable fuel pressure regulator lean the fuel out or what? Kind of a hijack, but it might help some other guys out on this thread.