I dont have one but I would say dont bother with it. The pipes are 2.25- so its bascially the same as stock. Im pretty sure they do have 02 sensor holes. I thought about gettting one but instead got a magnaflow x-pipe with cats. The magnaflow was more expensive but well worth it. You can always go with bbk or mac, etc. Probably even find something else on craigslist too. Only thing I regret now is, I registered my car where my parents live and they are in a county where you only have to smog your car when you sell it(instead of every two years), so now Im ready for an o/r mid pipe.
I'm not sure what mods you have or maybe you dont yet, but I'd say keep in mind eventually you will want more hp, want to add bolt-ons, and or add a supercharger, or a stroker motor- so you will evenutally want at least a 2.5 mid pipe. You might as well get a good one