I bought a used 95 gt vert (AODE) a couple of months ago. It was a running a bit sluggish (felt like it had no balls compared to my 85) so I gave it a needed tune up, but the car started running worse. The car now has a rough idle and when its cold it chokes for gas. I ran the computer tests and it said the o2 sensor was shot (it said left and right at first, but only right after i cleared the codes.) I changed it but the car is still running rough. 
I don't know where to go from here, I was thinking it might be the injectors but I'm pretty lost.

I don't know where to go from here, I was thinking it might be the injectors but I'm pretty lost.