My 02 reading stay at a consestent 600-900 mv. I this rich or lean and could this be a reason for some power loss?

 

A range of 600-900mV doesn't sound too consistant. 600mV is close to stoichiometic 14.7:1, and 900mV **might** represent a richer 12.0:1 or richer.

Under what conditions are you seeing these numbers? In closed loop, they should be switching frequently over the range of 0xx-9xx mV. At WOT, you should be seeing numbers in the 850-925mV range. But the stock O2 sensors aren't all that accurate at the PE mode A/F ratios, so they are not real useful for tuning. But if you're seeing 600mV at WOT, is quite liekly that its running lean, to the extent you could be getting some knock retard, and losing power.

 

My O2 mv readings bounce back and forth from 100-900. They appear to be completely random with no sense of order when at idle. WOT is 860-880mv.