anyone think my car would run better if i put the downstream o2 sensor in the pipe and hooked it up again, right now the plug is just hanging there, not sure if that causes it to ignore both, or just the downstream sensor, looks like it runs a little lean by looking at the plugs, its doesnt seem to run bad but i wonder if id get more power by having the 2nd one so the PCM isnt so flipped out, its already got enough stuff missing to get 8 or 9 codes

 

It should run better with it hooked up.

 

I disagree with das2123, the only function of the downstream sensor is to monitor the performance of the cat. converter...
You will get yet one more code - but driveability will not be affected.

 

thats what i thought it was for but ya never know

 

if you are looking for that last bit of power i would look into a "black box" (read about it but can't remember for the life of me where). this will hook up to the 2nd o2 sensor lead and trick the comp into thinking the o2/cat is in place and working right. this will give you a better mix and maybe a bit more torque. hope it helps, good luck.