actually the one I've seen for the lancer eliminates the second cat conv. would that make a difference, if say, the inspector saw I had one cat under there. Does only eliminating 1 cat do any good?

hmm...good question, cause I know some cars have a "cat" on the down pipe right after the headers... like on my SpecV. I got a new header and it eliminates that one, I'm sure as long as there is ONE in view you will have no problem.  as far as effectiveness goes.. yeah, it will help.  the less restrictions on your exhaust the better off... the fun thing about exhausts is that when it goes through the pipe it has a "flow" per say.  it resonates inside the pipe creating "exhaust waves"  and everytime you have a bend, bottleneck, or s**t in the way (cat) the waves get messed up and create back pressure.. some is good, too much is bad cause it will come back through.  so.. bigger is better ( to an extent 3"max!) and less bends and restrictions the better. 

this is the whole reason behind the test pipe.  it eliminates the main blockage in your exhaust and lets it flow more freely.  also you gotta have it so you can blow fire out the ass end!  cause thats just cool.