HP_Addict

I just got Autotap and am digesting all the information. The mV output from the O2 sensors is directly realted to the air/fuel ratio. However I have come across conflicting tables as to what this relationship is? Does anyone have an accurate table that goes from O2 mV to A/F ratio?
Thanks for the help

RWTD

O2 voltages aren't accurate for a/f ratios, other than stoich (14.7), but they can help to a degree, but just do not rely on them, please. I suggest a true wideband meter. You can purchase a very accurate one for a great price from http://www.innovatemotorsports.com/ . It can be had for around $350. Dynojet is also releasing one in Jan. for around $530. It also datalogs (via USB!). It's one awesome piece of equipment! Check it out:
http://www.widebandcommander.com/productinfo.htm

Back to using just the O2's, normally .890 to .910 indicates 13.1 to 12.9 (in that order; the higher the # on the voltage the richer the mixture), but this can vary greatly from vehicle to vehicle. Here's a chart that'll help somewhat for you:



I hope this helps!


[Modified by RWTD, 2:04 PM 12/22/2003]

HP_Addict

Thanks for the chart. I understand O2s are not that accurate and I would only tune on a wide band dyno. I want to use the numbers simply as a reference to get me in the ballpark. Hopefully to warn me of an unusual condition before some bad happens. So what is the accpeted rich/normal/lean mV ranges?