I tried it for a while. It sucked ass. You have to switch between modes to even see it. For on the fly curve adjustments you need a good a/f gauge. I personally use the autometer. I run my car at the 4th green led(aprox. .9164 volts) at WOT. (which on my afc is like -18% @ 5000 rpm with a walbro 255 pump). I don't think the "blue wire mod" is good at all. Just get a a/f gauge. Shoot get a digital one from jumptronix, I sure wish I had one.