Reading into LTFC figures.

[ae2598 at wayne.edu]

Is that the way O2 sensors typically fail?  Gradually, giving false
readings as the degrade, rather than all at once and setting a fault code?

I've got a Bravada with 146K miles on the original O2.. time to change? :)

On Wed, 17 Jan 2001, Richard Wakeling wrote:

> Hi Ross,
>     How old is the O2 sensor? Might be a good idea to fit a new one, reset  your
> BLM  to 128 and see if the same learn pattern develops. I come across many
> faulty O2 and they seem to fail in different ways. Try logging O2 against closed
> loop. This often helps me in deciding if the O2 is Strange. How long is it
> taking the O2 to start operating from cold? You will find a new one will get
> going real quick.
>     I have had cars come to me that run like dogs and just resetting the BLM was
> enough temporally  to cure the derivability until it reprograms its self back to
> being undrivable due to a faulty O2 sensor.
> 
> Cheers Richard.
> 
> Ross Myers wrote:
> 
> > Hi All,
> >
> > Been doing some ECM logging lately (which is O.K as far as the greenies
> > go!!). Anyway, the LTFC values on my car tend towards the calibrations
> > possibly being too rich, with most of the LTFC numbers down around 117 or
> > so.
> > But I am wondering. This is a single O2 system on a V8, so the left bank is
> > really determining the overall mixture readings, correct?.
> > What if 1 cylinder is not firing nicely and is tending to drive the O2
> > readings rich.
> > How can I determine if it is a Calibration issue, a lazy O2 (although it
> > seems quite active on the data I'm getting) or a slight misfire?.
> > I'd like to somehow establish the motor and sensors are 100% mechanically
> > O.K before I go taking out fuel in the cals.
> >
> > Thanks,
> > Ross Myers
> > Melbourne, Australia
> > E-mail : ponty at axis.jeack.com.au
> > Stuff : http://www.jeack.com.au/~ponty
> > <><><><><><><><><><><><><><><><><><><>
> >
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