There are two types of sensors, narrowband and wideband.
The narrowband is what you find on most vehicles, and comes in one and
three wire types. It is designed to measure accurately around the airfuel
mixture ratio of 14.7 to 1, which is also known as stoicometric(sp). This is
the figure that catalitic converters run at the correct temp, it is the
sensors job to give the EFI computer feedback so it can maintain this AFR.
Best power is made around the 13:1 mark and can be run as lean as 15:1 and
up when cruising, depending on the engine. Although they are narrowband,
these sensors can be used to give you a rough indication of if you are
running in the 12:1 to 15:1 (approx) area. They output a voltage reletive
to the AFR, but not in a linear fashion, the scale is expanded in the 14.7:1
AFR region.
The three wire sensors use a heating element to bring the sensor up to
operating temp straight away, the one wire sensors need a minute or two of
running before they start working.
The wide band sensors work in the same way but have an expanded voltage
scale so are acurate over a wide AFR range. They are also much more
expensive to buy.
To read a sensor you need a voltmeter, I use a simple bargraph display, the
centre of which is 14.7 AFR. I can provide a circuit if necessary. The
output voltage is around .7volts near 14.7:1.
Most oxy sensors dont like leaded fuel for very long, but will last a few
weeks, certainly long enough to do some tuning. You can pick them up cheaply
at a wreckers or Japanese parts importer. The last one I bought cost $10aus
secondhand.
Hope that made sense, and that it is correct, my memory fails me
occasionally, feel free to ask more questions....
Adam Fox
----- Original Message -----
From: Daniel Neuman <dneuman@hodge.sfsu.edu>
To: <datsun-roadsters@autox.team.net>
Sent: Saturday, May 12, 2001 9:46 AM
Subject: oxygen sensors
> Hello All,
> I am thinking of installing an oxygen sensor in my car to aid in tunning
> and just for the heck of it.. I figure that my car jsut needs yet another
> gadjet. Does anybody have any experience with them?? I hear that the
three
> wire type is more accurate than one wire and then I have heard that the
type
> of meter you get to read them is important also???
> Anybody have any helpfull info??
> Thanks,
> Daniel 69 2000
> SF CA
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