o2 sensor placement.
 

just wondering, i know that having the o2 sensor too close to the turbo can kill it, but how different will it read compared to say, one thats placed right before the cat, or one thats stuck into the tail pipe on the dyno?

recently went to the dyno, and idk whats up, but my o2 sensor read in the 11's while under boost and yet on the dyno, it went completely off the scale. idk what i should do about it.

ill try a free air calibration again, but i dont think that is it.

by the way, i have a heated element o2 sensor on the stock fc down pipe bung.