Boost detection

[Dale Ulan]

> They can give you at least a binary rich/lean indication, which is better 
> than nothing. As far as telling you "how rich", I can't say I really care.
> Sure, it would be nice to have a perfectly linear device that would allow
> you to have some sort of an accurate tuning equation, but I can live without
> it. 
> 
> I heard the 4-wire heated sensors were closer to being linear. Comments?
> 

Standard O2 sensors actually are almost useless unless you use it to
run an oscillating control system. They don't give very accurate
readings unless you oscillate them, for some reason. The output
of the O2 sensor depends highly on temperature, which can change
a lot. THe SAE readings on sensors for the past 20 years is a great
place to get an idea of how they work.

Some '4-wire' sensors are just heated ones... you have to get the correct
'pump' type O2 sensors. These often have 5 or 6 wires on them...
check a Honda Civic SI. These use the sensor, and it costs
about $400. It also needs some wierd driver circuit, which I haven't
tried yet...

-Dale