I won,t believe it until I see it. Of coarse Subaru may have a defect in
their OBDII code. Bad enough to cause fuel economy problems you could
definitely see on the graph of the sensor.


"Michael Pardee" <michaeltnull@cybertrails.com> wrote in message
news:SZWdnVRoC4JHVNHZnZ2dnUVZ_s-dnZ2d@sedona.net...
> "Woody" <TheDuck@pond.net> wrote in message
> news:8s33g.69065$H71.136@newssvr13.news.prodigy.co m...
>> Am 89 is not OBDII compliant and does not monitor the sensors that close
>> and the sensors are totally different. The OBDII system monitors heater
>> current and voltage and switching times and voltage to very precisely
>> determine what they are doing. The chance of them causing a problem
>> without setting a code is extremely slim. They can be setting sub codes
>> long before turning on the light on the dash. The information in the
>> computer should be thoroughly analyzed as swapping parts is expensive and
>> could just be masking the real problem.
>>
>>
> I would have thought OBDII would catch O2 weakness, too, but as the Subaru
> experience illustrates it isn't necessarily so. I am puzzled what sort of
> out-of-the-box defect the sensor would have that would cause it to behave
> so badly and not be tattled on, though.
>
> Mike
>