Originally Posted by Warrtalon

Sigh. You obviously haven't done any searching, which is what you should do before wasting our time. A flash is a flash is a flash...it just changes your ECU settings to provide more horsepower according to the mods you have. If you just get a basic mail-in flash, then you will get some power. If you have it all custom tuned on a dyno, then of course you will get the most power, because it will be CUSTOM DESIGNED FOR YOUR CAR, your mods, your gas, and your weather conditions. Either way, you probably won't get 300awhp on 91oct, unless you have an 05 MAYBE.

The fuel pump and DV are just accessory parts that ALLOW YOU to reach 300whp more easily and safely, but they don't add hp in and of themselves.