boogiesuperstar

There is a performance chip on this site called yourhotcar.com. Should I try it out or is there is anyone who has used it already, that can give me some insite on how accurate it is. Here is a link to the site and how the chip works: http://www.yourhotcar.com/prod/Surge_Engin...nce_Chip/17558/

On my IS350, would an aftermarket exhaust lower my gas mileage or help to increase it. If so, is it better to go with stainless steal or aluminum mandrel bend piping?