Test pipes for the 350Z and G35 These pipes completely remove your factory catalytic converters and relplaces them with a straight through design. This provides the absolute most flow possible which has shown gains on NA 350zs between 4-8HP making it one of the best "bang for the buck" mods. These pipes are an abosulte must on FI cars which need all the flow possible. Constructed entirely of stainless steel and feature thick 3/8" flanges. They are completely TIG welded and also feature seamless mandrel bends. Tube diameter of 2.25" matches up perfectly with aftermarket exhausts like Borla, Injen, and Nismo. They retain the factory oxygen sensor mount and WILL NOT THROW A CHECK ENGINE LIGHT when run. These pipes will definately make your exhaust note more aggressive. They have also tended to add a "raspy" exhaust note through the 3-4k range. This note has been loved by some, and hated by others, so it is not for the conservative. They use all factory mounting points and there is no modification to the vehicle. These will work with either aftermarket headers, factory headers, aftermarket exhaust, or factory exhaust. **please note that these replace your factory converters with straight pipes which will not pass SMOG! These are for off-road use only**