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<E-30> Re: O2 sensor checking

> From: Larry Schwarcz <[email protected]>
> Date: Wed, 07 Aug 96 19:34:58 -0700
> Subject: <E-30> O2 sensor checking
> 
> I'm trying to check my oxygen sensor on my '90 325iC (E-30)
> and it failed the first test in the Bentley manual!
> 
> After I got home, so car is fully warmed up (well, about 15 
> minutes after I got home), I disconnected the O2 sensor and 
> checked the voltage.  Should I get some voltage?  If so, how 
> can it give me some voltage when it's disconnected?

Yes, you should be able to read some voltage while the engine is running. After
the car is shut off, you will likely read nothing (0V). The voltage should be
small, between 0 and 1V.

BTW, it seems that "oxygen sensor" is a bit of a misnomer, as it registers a
voltage proportional to the amount of unburned hydrocarbons in the exhaust. The
higher the HC, the higher the voltage output. I guess that calling it an
"unburned hydrocarbon sensor" is too hard.


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Russ Poffenberger               Engineering Specialist
Schlumberger Technologies ATE   DOMAIN: [email protected]
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