When the designers made the Z back in the 90's they want to make the Z the best efficient cars ever made. My Z was non turbo had it changed to TT. EGR was deleted and ran a straight pipe on the exhaust system. I live in Fla so no smog test. Took out my AIV system. Plug up and delete some of the intake platinum hoses. It make it so much easier to work on the Z. It ran great no problems what so ever. You can order all the parts from Z1 Motor sports or CZP. Google how to do it if you like to work on your own car.