Air/Fuel Ratio

Is there anyway to get an AFR reading from an O2 sensor ? Like input 12 volts on on side to heat it up, then check the voltage on the other side . If I can get this screwball method to work, is there anyway to convert to the volts to an AFR reading ?

Jamey I still have that screwy looking O2 sensor that came out of that pipe, the one with the blue wire and wierd plug that wont fit my harness.

Answered my own question

AIR / FUEL RATIO GAUGE
I always thought there was some mysterious circuit needed to make this measurement. The reference below explains that the O2 sensor GENERATES a voltage that you can measure. This voltage is a comparison of the oxygen inside the exhaust and the oxygen in the outside air. There are even self tapping sensors that do not have to be welded into the exhaust pipe. If you measure this voltage with a high impedance digital voltmeter, you will get readings :

1.1 volts (rich)
0.45 volts (proper ratio 14.7)
0.2 volts (lean)



All on this page http://www.california.com/~eagle/instr.html

Wow, that was easy. :tongue:

I think that O2 sensor went to one of those Edelbrock AF Meters.

That was a waste of $130.

I strongly suggest the purchase of a wideband meter to anyone serious about tuning on their car. :tu:

I'm looking pretty hard at Dynojet's Wideband Commander. I'll probably pick one up this weekend off of ebay for the 85.

If the sensor you have had 5 wires then it is a wideband sensor, they require a control unit to opperate and read, but they provide extremely accurate A/F readings. You can use a norrow band O2 sensor (standard O2 sensor with eith 1,2 or 3 wires, along with a digital voltmeter to get a rough idea of your A/F ratio

I have a good graph on my website with fairly accurate data, but remember that a standard O2 sensors output does change slightly with temperature and is biased at stychometric.
http://www.telusplanet.net/public/gilesij/Volvord/carb_jet.htm

I personally use a wideband unit http://wbo2.com/2a0/2a0info.htm with this display http://wbo2.com/ld01/default.htm

Thanks for the info. Looks like great work you have did there, alot of research.

If you like, you can post it in a topic here and I will sticky it at the top for ya.

Thanks
I posted the article on the General Tech forum