Oxygen sensors why are they gone?

[Connectorhector]

So I bought a 95 GT and took the engine apart it's in the machine shop now but when I took the exhuast off there was two holes where I thought the oxygen sensors went only there werenone there. Is this common he had put CAI and upper and lower intake(BBK I think). MSD coil, rotor cap and that's about it. I'm just wondering because my buddy told me oxygen sensors should be there but there not. I'm boring40. Dipped and decking it. Polished and balanced the crank. New bearings everywhere. Got new KB pistons. Kept the rods but drilled them for better bolts. Also I got a PRO COMP 190 heads. Still gotta get a cam and headers. Do I need a oxygen sensor in the exhaust. They are not there for sure. When I put it back together will I have to worry. The car ran fine before I started besides the valve leak which is why I started. That was a mouthful. Lol. This is my first rebuild so any help would be awesome.

 

[CC'S95GT]

is the wiring there for the sensors?
There is no reason to remove them except they were bad and the PO was to cheap to get new ones.

 

[Connectorhector]

I know that I seen one for sure but there is snow on the ground but I'm sure there must be two. Obvously that's why the check engine light was always coming on. So what exactly do the o2 sensors do? I'm gonna get them anyways but I'm curious. Like I said my first rebuild. I thought I knew a lot but Definately a lot more to it than I remember from high school in early 90s. Lol

 

[lutter94]

O2 sensors sense the air/fuel ratio. If its rich, it cuts the fuel back, if its lean, it dumps in more......Sounds like a pretty extensive build, it might not hurt to go with a wideband. Want to know more, read this....

http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=48

 

[ttocs]

sure its not the stuff for the EGR plumbing?

 

[Connectorhector]

the one i remember seeing with nothing plugged into it was on the drivers side(i think it was the o2 but lol)