tips is what I need.
I bought a generic air/fuel ratio gauge for my 95 850 turbo.
I know these get readings from o2 senors...is there a way to tie the gauge into the existing o2 sensor?
If not, where should I place a new o2 sensor for the gauge?

 

If it is not a wide band setup it will not help much on the 850. Yes it can be hooked up but is not really all that accurate.

 

It wasnt till after I bought the gauge that I notice some were narrow band and some wide band gauges.....and the 1 I bought doesnt even say on the ad which it is.

Here is the ad: eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Can it be hooked up to the stock o2? And the 850 has 2 o2 sensors right? So which should it be, pre-cat or post cat?

I saw some vids on utube and noticed these gauges can move all over the place (dont seem very accurate) but figured it may give a general sense of how she is running. Plus, gauges just make the interior cooler

Ah, found the same unit in another ad...its a narrow band. I assume that wideband are more expensive/accurate.

 

Yes the wide band is WAY more accurate. The narrow band in these cars are just a light show.
It can be hooked up to the front O2 if you really want to do it. I just do not remember the colors off hand of the wires.