The Sniper internal programming makes a lot of assumptions. If you have a very generic car (350 chevy crate engine for example) the out of box Sniper will work okay. Most of what I work on is 600 to 700 hp big block Mopar engines with performance cams. The default programming will not work very well on an engine like that. It really isn't much different than a carb. If you have a stock 350 crate engine an out of the box carb will work. If you have a race engine you most likely need to have the carb tuned by a professional. EFI is the same way.