Yeah I think I will leave it out for now and if I find it way too loud then I will put one back in. I agree that it should at very least not make any difference, but as far as i hurting performance by taking it out so long as I still have the O2 sensor then I can't really see it. I mean otherwise why would companies have any market for a "high flow" converter. If better flow through your converter made things worse nobody would buy one.
I talked to the garage again and mentioned the O2 sensor and he said not to worry he has a o2 nut that he welds to the pipe drills a hole and basically sets it up the exact same as it was with the converter. Thanks all for your opinions. I just hope that it won't be too loud while driving steady highway speeds.
Oh and on another note does anyone have a magnaflow or any type of muffler on an accord with a dual 3" tip on it? If so how does it fit. Or am I better off going with a standard single 4"?

Magna77