Will i sacrifice fuel economy if i put in a cold air intake? Last time i gutted the stock air box and took out the resonator my fuel economy went way down and i didn't feel an increase in power. I know i can expect and increase from a CAI but how will fuel economy be affected under the same driving conditions as the stock air box?

Makes no sense to me. You have a supercharged engine.
Your fuel economy should increase with any decrease in intake or exhaust restriction.
The only reason your mileage would decrease is if you were into the loud pedal a lot more than before.

How much did your fuel economy go down? I'm sure whatever caused it was not the fact you gutted the box though. That or a CAI will increase efficiency slightly. Unless you put a "Tornado" or "Fuel Genie" in it. But I know you didn't do that.

Maybe your O2 or something happened to go bad at that time? :?

Anything that makes the engine more efficient is going to give you better gas mileage, which makes the common myth that mods reduce gas mileage false, because to make more power you usually have to make the engine more efficient. Any time you open up the intake or exhaust on an engine you are allowing it to breathe easier making more power and giving better gas mileage. So, I see no reason why a CAI or gutting an airbox would reduce gas mileage. If you see a loss in fuel mileage with a CAI I would suspect another problem.

I think that typically people drive a bit differently after mods, therefore the supposed "decrease" in fuel economy. But some mods can decrease fuel economy, like adding a turbo or supercharger, something major along those lines.

I suspect another problem too unless he gives it WOT every minute he'* in the car. His fuel economy went "way down"....SSEi, how much did it change? Within a couple days back in January my mileage dropped a lot, but I changed my PCV, plugs, fuel filter, and O2 sensor...and was fine.