Thats weird, I didn't realize the s14 and pignose CAI looked so similar. The hole in your MAF adapter can be used for the IAT (Intake Air Temperature Sensor), which S14's have but S13's don't. That "black box" that 240sxAli4Life was referring to is on the S13 and can be left disconnected. It shoots certain exhaust gasses back into the intake system, so leaving it unplugged does no real harm.
This is how it should look when its all said and done:
(ignore the extension that places the filter down behind the bumper.)