450mV is 0.45V meaning that you are getting a signal.  It is best to measure
this with a analog multimeter as most digital ones are too slow to read the
always fluctuating output of the O2 sensor.  It should be, on a correctly
tuned vehicle 700mV plus AND minus 200mV with the average being 700mV.

David Marshall

Fast Forward Automotive Inc.
4356 Quesnel Hixon Road
Quesnel BC Canada  V2J 6Z3

http://www.fastforward.ca    mailto:sales@fastforward.ca
Phone: (250) 992 7775        FAX: (250) 992 1160

- Vanagon Accessories and Engine Conversions
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-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Ben huot
Sent: May 6, 2002 11:20 PM
To: vanagon@GERRY.VANAGON.COM
Subject: A damn OS question again, yea!!! now i need some help, it's my
turn....

Hi guys, i receive my new Oxygen Sensor today

but i don't see any difference with the old one!!!!

One question:

Many people are saying that an OS produce voltage when hot and unplug!!!!
Between 0.1 to 1 volt. (rich mixture or poor mixture)!!!!!!!!!!!!!!!!!
For now I don't agree!!!

Should I unplug the battery to reset the ECU?

Explanation: I get the van too normal operating temperature (OS is plug); I
unplug the OS and test voltage to this one (ground the negative and I touch
the OS sender wire with the positive of the voltmeter); I get about 450MV
(it means no reading), I never get .1 to 1 volt. If i touch the van side of
the OS wire only I get a steady .5 Volt when the OS is unplug. When i plug
back the OS (Van running and hot) it get down to 450MV or so but sometime
it give me a brief .7 volt and it goes back very fast to .350MV or no
reading!!!!!. (back and forward) I never get a steady reading; yes my
voltmeter wires are well attached.

What are your suggestions?

Best regards, Ben
http://www3.sympatico.ca/huotx/engine1.htm

Ps: I have 2 new OS sender (error from the company) and the old one, they
all give me the same reading!!! Is my $100 voltmeter faulty!!!!