Technical O2 sensor question

Post by **jonnymopar** » Mon Mar 05, 2007 9:23 am

Does anybody know, or know where to find, the relationship between the voltage output and the actual A/F ratio of a regular narrow-band O2 sensor? As in... say my O2 sensor is putting out 0.70V. What A/F ratio does that correspond to? Thanks.

me · Post by me » Mon Mar 05, 2007 9:31 am

as you can see there realy is not that much that you can learn from the voltage. it is rich or lean, not much in between

Post by **jonnymopar** » Mon Mar 05, 2007 12:39 pm

Shit, I didn't expect to get that kind of information that fast. Thanks!

I'm doing everything I can to work with a narrowband sensor because I cringe at spending so much money on a wideband. It measures voltage, nothing else. Big deal, it measures 0-5V instead of 0-1V. Why they're $300, I'll never understand.

fixitmattman · Post by **fixitmattman** » Mon Mar 05, 2007 1:09 pm

Narrow bands are cheap because they're simple. They're basically a rich/lean switch. High voltage for rich, low voltage for lean. A wideband generates a voltage output proportional to the excess air factor and you can use that voltage to accurately identify the excess air factor. If you find the voltage/excess air curve for a wideband it's completely different.

tooslow · Post by **tooslow** » Mon Mar 05, 2007 1:11 pm

I stole this from the mega manaul it shows the difference between narrow and wide band

Post by **jonnymopar** » Mon Mar 05, 2007 2:26 pm

Ah, interesting. I was unaware that a wideband output was opposite a narrowband output in the sense that rich = higher voltage with narrowband and lean = higher voltage with wideband.

Now, I thought I had read somewhere that some of the wideband setups you can get have a narrowband simulator output to feed back to the ECU. I would definitely like that because I'm running on re-calibrated stock electronics and I'm unsure that the actual hardware in the ECU would handle a 0-5V input even if the firmware could support it. Do all widebands have that?

tooslow · Post by **tooslow** » Mon Mar 05, 2007 2:47 pm

I know the aem has it and it was the cheapest option when I was buying got it for 255 of ebay
but not sure if the stock ecu would work with it

me · Post by me » Mon Mar 05, 2007 10:50 pm

get an LC-1 wideband it has two analog outputs one can power the pcm and the other a narrow band gauge (with the correct output not a light show either). with the LC-1 you can program the output voltage to be what ever you want, at what ever ratio. http://www.innovatemotorsports.com/ or you could go with AEM. that is really the easiest way to tune. good luck.

Post by **jonnymopar** » Wed Mar 07, 2007 7:00 pm

Ok, this LC-1 has peaked my interest. Basic, but functional. I don't need any fancy crap to go to my laptop or standalone fuel system because... well... this car won't have either! Plus it's under $200 and I can use my existing A/F gauge. Hmmm....