Cobb AP
 

Will using the cobb ap make me fail state emission inspection. Also how much hp can you expect to gain by using it?

I'm curious about this too.
With certain DTC codes being masked, would the inspector's reader give a fault error because of this?
Like when you clear the PCM before inspection and they read your car, only to say that not enough info has been collected and to drive around for 15 minutes and come back.
I encountered this when I swapped out batteries just before e-check.

^ i just slip a couple of greens in his pocket and call it a day....

hp is all dependent on what kind of mods you have on your car

You should be fine. The car runs leaner, thus cleaner.

the cobb should not make you fail. If anything it'll help by blocking certain CEL's