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https://www.autonerdz.com/cgi/yabb2/YaBB.pl General Public Area >> PicoScope >> O2 Relationships https://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1114921447 Message started by Tom Roberts on Apr 30^th, 2005 at 9:24pm

Title: O2 Relationships
Post by Tom Roberts on Apr 30^th, 2005 at 9:24pm

Victim: 2001 Ford Windstar 3.8
Capture: All four O2 sensors
Scope: Pico 3423 on a USB 1.1 PC
Method: Filtered Save On Trigger Session @32k samples per channel
Conditions: From start idling ending with a throttle snap

Here is the series:

Title: Re: O2 Relationships
Post by Carl Grotti on May 1^st, 2005 at 7:07am

Hi Tom,

It appears you are triggering off of the noise, but we don't see it because you have the low-pass filter turned on. Is that correct?

The O2s wake up pretty quick don't they? An open heater circuit would show up very easily.

Title: Re: O2 Relationships
Post by Tom Roberts on May 1^st, 2005 at 7:31am

Hi Carl,

Yes, it's triggering off of invisible noise. The low pass filter has cleaned it up quite nicely.

The engine was not stone cold, but had been sitting for a while before this start up. The O2s wake up very fast and are in closed loop in about 10 seconds.

BTW, the PCM was the test point. Accessing the O2 connectors on this would be a nightmare.