looking at diff bins and things i might try,, i see in tuner pro with my 7747 ecm that thier is a [02 idle afr bias value] [2f7]hex address. ---------can anyone give me info on this ?? as the bin im currently using has it at 109.00mv. and i see in alot of bins its at 0.00.

 

sounds like just another bias that a lot of the stock calibrations have. just minus it from the O2 rich lean stuff to get the value used by the computer.
Like how the spark advance has a bias, the O2 has a bias

-edit
don't quote me on this, but I feel secure in saying that

 

The value at $2f7 is added to the O2 window during idle. It is to make the idle richer from what is in the tables.

RBob.

 

sounds like 91 chevy is saying it is taken away fuel,, and rbob is saying its adding ?? Im a little confused ??? here.-------------------- Im also trying to figure out if im better with my lean/rich/mean values at same settings thru out most air flows like alot of stock truck bins, or is it better to say have lean/rich values different ,, and mean as central point.------------read up on it here but its difficult to completely under stand.--------i was thinking that you would want lean/mean values diff,,,as to cause 02 switching ??and mean as the central point.-- or am i way off here

 

I would go with what RBob said.