Nice WOT A/F there Hyundia.
Pulling the air intake off and not getting any gain doesn't absolutely mean that a good aftermarket one won't perform better overall though. Every turbo and all-motor car that I have pulled the intake off has done better with an aftermarket intake on it than none at all. Since it's a MAP based car though, you aren't going to see "gains" like you do with an Evo X with an intake, due to the intake changing the air meter instead of actually being a restriction.