Smog

I was curious if anyone here has passed emissions with either a high flow cat or even a test pipe. Do they really add that much more pollution? I might take the cat off if they do, but if its not really a prob, it gives my car a deeper tone. I put it on like a week after my smog test, so Im good for another year. Its a 96 obd2, I think thats before OBD2s checked the cat convertor, which is why Im guessing I didnt get a check engine light, not sure though.