Help with O2 sensor and poor power output

[crholla]

I just installed a PTE GT3255 turbo last night and went to the dyno today. I noticed that my front O2 sensor was reading 0.00volts fluctuating to 0.02volts. Is this how an O2 sensor behaves when it is bad? We made a couple pulls on the turbo, the best run yielding 260awhp at 4300rpm's (@20psi - this turbo is efficient from 20-29psi), power dropped steadily to 175awhp at redline. Anyway, would a bad o2 sensor cause the WOT performance to be bad? If it is not the O2 sensor that has gone bad, what else could be the cause of my 52trim turbo only making 260 peak hp? There are no boost leaks, I have an efficient FMIC, 650cc injectors tuned with AFC, Wideband O2 read at about 11.5-12.0 through the pull, what else could be the problem?

 

[crholla]

anybody have any thoughts?

 

[gixrman]

It is a stong posibility that it is your 02, I just had the same problem after installing my EVO16g. The o2 read 0v and the car ran pig rich and all of my fuel setting were way off. I was told the ECU goes to a backup fuel map so the car will at least run. I repalced the 02 and all is well. You may also check for boost leaks if you hav'nt done so allready.