Hi,
I need to know what the voltage range is that the o2 sensor sends to the ecu.

basically I want to use my multimeter as a makeshift a/f gauge.
and I can't access my helms right now..

So if someone can let me know what voltage its supposed to put out,
like what volt = lean what = rich etc..

thanks

 

not 100% but i think it reads from .1 to .9 volts .1= lean .9= rich

 

Are you gonna use a wideband or just a stock o2 sensor? If it's a wideband it depends on the sensor (anyway from 1-5v). If it's a stock o2 sensor, it's .1 to .99v but it's not really intended for performance and real time reading of the a/f it's mainly for emissions.

 

ok thanks guys.
yeah .1-.9 sounds right to me.

stock o2 sensor(wideband sure would be nice eh?)

And you're right, i'ts not a good meter for tuning and such.
so it's not really worth shelling out the money for an actual gauge,
which is why i'm trying to do it the free way. Just so I can see where it's at currently..

thanks.

 

using a multimeter is not that good, its to slow to see the switching, what would be better would be a DSO it shows a wave pattern but picks up the voltage but it cost big bucks, just get a wideband set up to watch it and tune

 

well i'm not interested in the crazy erratic reading you get at idle and part throttle

just WOT, and that is a pretty steady slow changing reading usually.

 

If your going to use your multimeter to check the O2 at WOT I can tell you right now its going to be somewhere around 800milli volts. No point the O2 only provides fuel control during idle and normal operation, at WOT the ECU allows the fuel mixture to run rich.

so ideal vehicle will run a 14.7 air fuel ratio, but at WOT prob 12.5 to 13.9 ratio.

 

hmm..

why would it be at 800mili volts?

shouldnt it just be a ghetto af gauge, cuz all they are is LED's hooked up to a voltage gauge really.. and i've had one,
at WOT it'll show somewhere in the midrange..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tad &raquo;</TD></TR><TR><TD CLASS="quote">hmm..

why would it be at 800mili volts?

shouldnt it just be a ghetto af gauge, cuz all they are is LED's hooked up to a voltage gauge really.. and i've had one,
at WOT it'll show somewhere in the midrange..</TD></TR></TABLE>

It's supposed to be arount .8 to .9v because at WOT the ecm switches to open loop and 100% duty cycle on the injectors... if you're reading lean or voltage around .5 then either you have a bad o2 sensor, or you're not getting enough fuel.

 

well fack, then does that meant that an a/f gauge is really utterly useless too?
(without a wideband at least).