O2 sensor display.

[Regnirps at aol.com]

In a message dated 4/18/99 2:51:01 PM, bearbvd at sni.net writes:

>I think Bruce meant calibrated with respect to A/F ratio, not voltage,
>Charlie.
>
>The voltage from a HEGO sensor has little to do with mixture ratio--it is
>more like a switch, saying RICH or LEAN.
>
>The HEGO sensors do tend to cross at stoich regardless of EGT or EBP, but
>how steep the crossing is varies VERY much with both of these variables.
>
>See above. Using anything but a wide band type UEGO sensor/and associated
>DYNO calibrated meter which compensates for EGT AND EBP, as required, 
>for
>performance work is foolishness unless you either have an infinite supply
>of money (in which case you would buy one of the available wide band units
>anyway) or have no respect for the engine you are trying to tune--cause
>you
>will damage/ruin/blow your engine if tuning by relying only on a HEGO
>sensor's output!!
>
>Regards, Greg

I figured he meant F/A ratio which is why I answered with the only thing I 
can really know, which is volts.

Basically I built what the local racers wanted -- more lights for more 
precision. It is set with 0.47 volts at the dividing line between green and 
red so a little noise lights them both. Non-racers with modern cars are using 
them just to tell if the system is working by seeing it "hunt" at idle.

At the moment I'm using one three wire and one four wire sensor pulled from 
junkyard Fords. I think they are like the popular Bosch generic sensor. This 
is the type the guys wanted to read.

I'm a physicist and it has taken me a long time to find ANY decent 
information on the sensor physics, and I'm not too pleased with what I have 
found so far, which isn't much. Not pleased because they do not behave the 
way my peers in the performance arena think they do. Any pointers to the real 
deal are appreciated.

Charlie Springer