First of all what is a stealth cai? I'm guessing you connected a cone filter to the end of your MAF tube? That is where most fo the intake noise is comming from. I believe the box in the engine bay is meant to reduce noise from the intake. You could either connect the MAF tube to the throttle body using the accordian tube thing that connects the resonator box to the TB and connect a cone filter to the end of the MAF tube (so its like a short ram intake) or buy a real CAI. Both of those would be louder, but neither of them would be stealthy anymore.