Re: What's inside an "O2 Sim"?
 

Re: What's inside an "O2 Sim"?
 

That link doesn't have a wiring diagram or anyhting; am I missing something?

Re: What's inside an "O2 Sim"?
 

There's more to it than that. The voltage isn't constant, but rather flucuates up and down to simulate real O2 sensors. True, it is still pretty much simple circuitry. I was guessing some sort of oscillator circuit.

What's inside an "O2 Sim"?
 

Seems likely to me that it's just a
plain old silicon PN diode. Something
to give you 0.3 - 0.7V at very low
bias current. Anybody ever take one
apart, or put one on a curve tracer?
Might just be that these $70 "simulators"
are $69.83 worth of mystery, $0.10 worth
of connector and $0.07 worth of diode.

This could suddenly become a "cheap mod",
if my hunch is right.