Hey guys, I'm building myself an air/fuel meter based on these instructions (www.scirocco.org/tech/misc/afgauge/af.html) and I wondered whether our cars used the same voltage scale?

I know O2 sensors are a standard but I wondered could anyone tell me whether these voltages and their AF ratios are about right for our cars? Perhaps someone with a multimeter and a real AF gauage can probe the o2 sensor to check?

0.97V - 12.1:1
0.88V - 12.7:1
0.78V - 13.2:1
0.69V - 13.8:1
0.59V - 14.4:1
0.49V - 14.9:1
0.39V - 15.4:1
0.30V - 16.0:1
0.20V - 16.5:1
0.10V - 17.1:1

Thanks for your help guys!




I was happy when I heard my car ran 10s. Then I found out that was 0-60.

Well I can tell you that this probably wont work. the o2 sensors on are cars are narrow band 02 sensors. they can only read to rich or lean. in terms of voltage this basicly just means more or less then a set constant. unfortunetly its not like you can just use a multimeter, you still need the sensor, if it were that easy you would see wide band guages for stock 02 sensors. sorry but youll have to drop 300+ like the rest of us.

if your still intrsested in making your own by using a wide band 02, I could post the voltage for my plx wide band using my Megasquirt.


"boobs now with Riboflabin"

True, true, I understand t he difference between wide and narrow-band O2 sensors, but don't people still run AF meters on stock sensors? I mean, it's not for huge accuracy but just for a general idea and more for fun than anything.




I was happy when I heard my car ran 10s. Then I found out that was 0-60.

well yeah, but theres really no point. I mean I guess if its a show car with nothing more then an intake or something. but your not going to get any kind of tuning done with it. (well safe tuning)

also Im not really against them, its just that those numbers are usless, sorry.


"boobs now with Riboflabin"

That AFR guage will work for general tuning. Thoes numbers look accurate. In the aldl tuning of a cavalier, from a 95 ecm, i'm looking at about thoes voltages, though in my jbody the o2 sensor sometimes goes to .092 mv for longer periods of time. Not sure why it does that, but i believe either i have a short somewhere or my injectors are dirty.

Anyway, you should be able to build a guage out of a multi-meter that reads the volts, but i wouldnt spend any serious money on it when you can get a self contained LC-1 from innovative motor sports for around $100-$200 which is a true wideband with a narrowband simulator for the pcm. I believe you can program the settings on the LC-1 also to tweak the fuel tune.