PLZ help MKIII VR6 exhaust questions

[=loki=]

Hi, I bought some new headers for my VR6 and I want to get them on soon.
The problem is I bought some cheap ones and I need to get some welding cleaned up, which is not a big deal.
My real questions are:
(1) the headers I bought have a tube welded onto one of the header tubes (leftmost one if viewing from driver position). I don't think my stock headers have that. Is it a temp. outlet or meant for CO2 tap? Do stock Vr6's ahve this on the headers? I can't see it on my car with the heat sheild in place. I want to just have it removed and the hole welded up.


(2) With these new headers, the outlet ports do not match the OEM gaskets openings. My question is do the stock header ports match the OEM gasket openings perfectly, or are the gasket openings bigger than the header ports.

(3) I have a heated O2 sensor at the base of the 2-1 collectors before the cat, and then another in the cat. During the upcoming exhaust job I want to get rid of the cat entirely. So..... will not having a cat mess up the O2 sensor (readings) that belongs in the cat?? Can I get rid of the cat O2 sensor entirely? and will this cause the engine light to be on all the time??

The reason why I'm asking is that I really don't want to put headers on my car that have ports that are too small. So I'm trying to figure out the fit before the job goes ahead.

Thanks if you can help I appreciate it.