I owned this kit. It worked for me well enough to tune for open loop. I had been on the dyno at the same time as reading my gauge, and it read pretty much the same as the WB on the dyno. I used to use my digital video camera pointing at the gauge and the tach. after doing some test pulls, I would pull over, replay it while watching both guages and adjust my SAFCII. It worked for me. It is a worthles POS in closed loop. I eventually sold it and went to the FJO. The O2 that comes with the kit is OK. Most people will say this kit is a POS, but in reality, if you set it at the right #, NOT the # the install papers say, it will work.