O2 sensor Voltage

[nacelp]

> I haven't read any of the ecm strategies, where can I get them (assuming
> you're not talking about ecu specific manuals)?

In the DIY+GMECM archives.

  If the ecu has some sort of
> time delay response, what if I output a square wave (minimum external
> hardware on the microcontroller) with a dc offset to trick the ecu?

What if's ain't gonna work.  You need to find out what strategy your ecm
uses...

The way
> I understand O2 sensors, the output voltage will resemble a sine wave
whose
> amplitude changes as the ecu adjusts for lean/rich conditions.

ECM, might use a high reference and low reference voltage, and measure the
time, above or below those references for rich lean, not max voltage.

Again, you got to figure out what you have.
There are some clues, that you need to look at. ie, TBI/TPI, O2 sensor sees
all cylinders, or just a few.  Is it heated, close to to head, etc.  Even
better is hacing the code.
Got to remember the oems in general make the stuff a little difficult so
that the average Joe can't defeat it.   They have to keep the emission folks
happy, and part of that is durability.  Meaning as ashless as possible for
the O2 sensor itself.
Grumpy

> >Might not be anywhere near that easy depending on your ecm.  Have you
read
> >about any of the ecm strategies for monitoring O2 v, and corrections?.
> >Some expect a specific response, and time delay from the O2 to changes in
> >injector timing.
> >Grumpy


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