High performance tuning chip

i know everyone thinks these plug and play can't work or are simply a joke and in most cases you'd be right and I'd agree with you but i took a chance on one of these I plugged this in and let it learn and how I understand it to work they told me to install it and forget about it for about 250 miles or so how it works is it learns your driving habits as it learns your vehicles parameters such as fuel curve, timing curve, and it cleans up your fuel curve to make it burn fuel more efficient along with refining your timing curve and puts timing in or takes timing out which ever it need better timing curve creates better more effective fuel curve and we all know it takes fuel, air, to make horsepower i could feel a difference in my car one morning late for work and I was leaning on my little import and I could actually feel it pulling hard so then I paid attention to my mileage and I gained 6 miles to the gallon and if all else fells you can use it for diagnostics for engine lights