Code 176 & 177 after new O2 install

[Prochrgd1]

I dented my drivers side O2 sensor while re-installing my engine w/trans on the firewall & decide to replace it with a Bosch stock replacement. The passenger side has less the 10,000 so I left it in. I now throw the above codes & can't figure it out for the life of me. My A/F gauge is hooked up to the drivers side O2 & reads Stoich all the time (used to pan all around) Seems to be running in default mode, smells of gas etc. Any suggestions on what could be wrong?

 

[jrichker]

The 2 codes given contradict each other.
The 176 code is System Indicates Lean (Bank No. 2).
The 177 code is System Indicates Rich (Bank No. 2).
Are you sure you didn't miscount the flashes?

 

[Prochrgd1]

I guess it's possible, but they ran the scanner twice. I think the O2 sends a rich signal, & the computer leans it out & vise versa. Thus throwing the codes. I just don't understand why, with a new O2 I would get these two codes.