Re: O2 sensor readout (Air/Fuel ratio in

[TACE96A@prodigy.com (MR NED BENNETT)]

Full throttle gives a fixed duty valve reading of 64% if memory serves.
Cold running is slightly higher.
I don't remember who asked about the accuracy of the oxs voltage reading,
but at Bosch school in Ill they rely heavily on this voltage for
diagnostics.  For example, a small vacuum leak, say a little vacuum
resevoir line is cracked, will produce hardly any driveability problems but
will give a voltage reading in the neighborhood of 1/10th of normal.  We
had a 88 5kTQ in our shop last week that read .1 v @ 4000 rpm in neutral
because the fuel pump delivery rate was half off.   Turbo intake leaks give
a similar figure. The thing I find interesting is how FAST the voltage
changes if you spray carb cleaner at that miniscule vacuum leak...I think
instantaneous is the idea.