I got a full magnaflow 2.25 setup with magna cat, if i take the cat out and go straight pipe will i notice much gain, and the simulaters that they sell do they block all CEL's and will they fool the emissions computer when i goto get a sticker?
you wont notice anything. its pointless to do. if you had high horsepower then you probaly could get away with it.
far as inspection, some places actually do a visual inspecion and make sure you have a cat

Im a Xbox 360 fanboy...and damn proud of it!!