This is my first car that i would like to do some mods to. My questions is what mods will cause my car to not pass emmisions?

 

Replacing the catalytic converter with a midpipe (straight piece of pipe) will probably get you the most hp, but it will make your car incredibly loud and it won't pass emissions. Other than that a cat back, air intake, pullies, etc and you are fine.

 

What about FI ?

 

Many of the supercharger options (not on the RX8, but in general) ala Vortech, Paxton, & ATI's have CARB emissions stickers, but most of the turbos do not. Your best bet is to check into your state. I live in Cali. and it is pretty stringent out here. In general a lot of the turbos won't pass emissions. I heard that was one of the reasons they did not have them on the RX8's...could be speculation though.