yay i gutted my cat on my 00 si cuz it was clogged and caused me to fail emission test so i gutted it and i passed emissions and have no CEL...the dude at the inspection place even told me after i did it that you could do that and most times it would not throw a CEL...i thought it would but that was more the 6 weeks or more and still no CEL...though i have noticed a slight decrease in MPG and when i stomp the throttle the gauge goes down quite aways but then comes back up...haha