This unit is very well made and works perfectly. You do have to find a shop with a dyno that has a wideband air/fuel ratio monitoring to fully calibrate it. The second gen unit is calibrated by a laptop or PC. I have mine running pretty good, but still need to get it fine tuned. I am thinking of getting a wideband O2 sensor system so I can monitor and accurately tune it on the fly myself. Please feel free to email me with questions........smangum4@home.com