For you future thread searchers and other oxygen sensor newbs like myself..
Dads 1994 Corvette failed emmisions, and was bogging, and running poorly. Using datamaster I discovered the right oxygen sensor wasnt working properly.
Their are 2 oxygen sensors on the 94's left and right side both pre-cat. Their both a pain to uninstall and install, left is a bit easier than the right.


Left Side (driverside)- Lift car, support safely and crawl on under. Couldnt get an open ended wrench on either of the sides, the heat shield on the exhaust sticks out making it hard to reach it, so I used a pipe/monkey wrench to loosen them up (run the car and heat up the exhaust, let it cool enough so you wont burn yourself). Installing the sensor I used a bit of high temp gasket (dont get this on the sensor part), and hand tightend as much as possible. I then used the monkey wrench to tighten, but needed to be real careful not to damage the tube (it doesnt need to be real tight). It bent in alittle, but all works fine.

Right Side (passenger) - This side was harder. It didnt seem possible to get it off without dropping the exhaust but it can be done! I completely ripped the top part of the sensor off with vice grips and a monkey wrench, because it wouldnt come off (I forgot to warm up exhaust this time, so it may come off at first try for you.) I could then get a 7/8 socket on the sensor. Then from the top of the car, I managed to use the bar from my hydraulic jack and stuck it down by the socket wrech and used it for leverage to loosen the sensor. It eventually came out! I installed it the same way as the left side.

So the short version = First warm up the exhaust and crawl under car with a monkey/pipe wrench.

Thanks for the help everyone.