From: Ray O on

"Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message
news:Xns9B74A7A9D94D5SntzldfrdSntzldfrdco(a)216.196.97.142...
> "larry moe 'n curly" <larrymoencurly(a)my-deja.com> wrote :
>
>> Sarah Houston wrote:
>>
>>> After doing some extensive reading, it began to come clear how the O2
>>> Sensor performance could be off, yet not be able to see any symptoms
>>> (other than lower gas mileage) with the tools I was using. It turns
> out
>>> that the O2 swing cycle shown in the photographs is the swing time of
>>> the overall system and not just the O2 sensor itself. To really
> examine
>>> the performance the O2 sensor, for example to determine if it was
>>> developing a lean or rich offset, one would have to use a digital
> volt
>>> meter with an averaging feature connected directly to the sensor and
>>> look for the 450mV centerline signal in a known, properly performing
>>> system centered at the 50% duty cycle.
>>
>> Are there digital voltage meters that don't average semi-fast
>> signals? I think for testing O2 sensors, a meter with a fast-reacting
>> bar graph would be better.
>>
>>> To measure responsiveness, one would have to use a laboratory scope
>>
>> Why? It's just a low frequency signal that any regular scope, or even
>> a cheapo handheld 1 MHz scope/DVM can display.
>>
>> Do any owner's manuals mention a replacement interval for the O2
>> sensors, that is, for vehicles made since the mid-1980s?
>>
>
> I googled and found:
>
> http://www.autohausaz.com/html/emissions-oxygen_sensors.html
>
> Oxygen Sensors Don't Last Forever
> Here's What Happens As They Age
>
> As an oxygen sensor ages, contaminants from normal combustion and oil
> ash accumulate on the sensing element. This reduces the sensor's ability
> to respond quickly to changes in the air/fuel mixture. The sensor slows
> down and becomes "sluggish".
>
> At the same time, the sensor's output voltage may not be as high as it
> once was, giving the false impression that the air/fuel mixture is
> leaner than it actually is. The result can be a richer-than-normal
> air/fuel mixture under various operating conditions that causes fuel
> consumption and emissions to rise.
>
> The problem may not be noticed right away because the change in
> performance occurs gradually. But, over time, the situation will get
> worse, ultimately requiring the sensor to be replaced to restore peak
> engine performance.
> ...
>
> Don't Wait For Failure
> Replace Your Oxygen Sensor as Normal Preventive Maintenance
>
> To minimize the consequences of normal aging, Bosch recommends oxygen
> sensor replacement for preventive maintenance at the following
> intervals:
> Type of Car
>
> Mileage Replacement Interval Recommended
> Unheated oxygen sensors on 1976 to early 1990s vehicles
> Every 30,000 - 50,000 miles
>
> Heated (1st generation) oxygen sensors on mid-1980s to mid-1990s
> vehicles
> Every 60,000 miles
>
> Heated (2nd generation) oxygen sensors on mid-1990s and newer vehicles
> Every 100,000 miles
> _________
>
> I'm not sure what the 93 7AFE has, does anyone know?
>
> I can just look under the hood...
>
> when the weather warms a little, it's -1 here in west Denver right now.
>

First generation heated O2 sensor
--

Ray O
(correct punctuation to reply)


From: Sarah Houston on
"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote :

>
> "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message
> news:Xns9B74A7A9D94D5SntzldfrdSntzldfrdco(a)216.196.97.142...
>> "larry moe 'n curly" <larrymoencurly(a)my-deja.com> wrote :
>>
>>> Sarah Houston wrote:
>>>
>>>> After doing some extensive reading, it began to come clear how the
>>>> O2 Sensor performance could be off, yet not be able to see any
>>>> symptoms (other than lower gas mileage) with the tools I was
>>>> using. It turns
>> out
>>>> that the O2 swing cycle shown in the photographs is the swing time
>>>> of the overall system and not just the O2 sensor itself. To really
>> examine
>>>> the performance the O2 sensor, for example to determine if it was
>>>> developing a lean or rich offset, one would have to use a digital
>> volt
>>>> meter with an averaging feature connected directly to the sensor
>>>> and look for the 450mV centerline signal in a known, properly
>>>> performing system centered at the 50% duty cycle.
>>>
>>> Are there digital voltage meters that don't average semi-fast
>>> signals? I think for testing O2 sensors, a meter with a
>>> fast-reacting bar graph would be better.
>>>
>>>> To measure responsiveness, one would have to use a laboratory
>>>> scope
>>>
>>> Why? It's just a low frequency signal that any regular scope, or
>>> even a cheapo handheld 1 MHz scope/DVM can display.
>>>
>>> Do any owner's manuals mention a replacement interval for the O2
>>> sensors, that is, for vehicles made since the mid-1980s?
>>>
>>
>> I googled and found:
>>
>> http://www.autohausaz.com/html/emissions-oxygen_sensors.html
>>
>> Oxygen Sensors Don't Last Forever
>> Here's What Happens As They Age
>>
>> As an oxygen sensor ages, contaminants from normal combustion and
>> oil ash accumulate on the sensing element. This reduces the sensor's
>> ability to respond quickly to changes in the air/fuel mixture. The
>> sensor slows down and becomes "sluggish".
>>
>> At the same time, the sensor's output voltage may not be as high as
>> it once was, giving the false impression that the air/fuel mixture
>> is leaner than it actually is. The result can be a
>> richer-than-normal air/fuel mixture under various operating
>> conditions that causes fuel consumption and emissions to rise.
>>
>> The problem may not be noticed right away because the change in
>> performance occurs gradually. But, over time, the situation will get
>> worse, ultimately requiring the sensor to be replaced to restore
>> peak engine performance.
>> ...
>>
>> Don't Wait For Failure
>> Replace Your Oxygen Sensor as Normal Preventive Maintenance
>>
>> To minimize the consequences of normal aging, Bosch recommends
>> oxygen sensor replacement for preventive maintenance at the
>> following intervals:
>> Type of Car
>>
>> Mileage Replacement Interval Recommended
>> Unheated oxygen sensors on 1976 to early 1990s vehicles
>> Every 30,000 - 50,000 miles
>>
>> Heated (1st generation) oxygen sensors on mid-1980s to mid-1990s
>> vehicles
>> Every 60,000 miles
>>
>> Heated (2nd generation) oxygen sensors on mid-1990s and newer
>> vehicles Every 100,000 miles
>> _________
>>
>> I'm not sure what the 93 7AFE has, does anyone know?
>>
>> I can just look under the hood...
>>
>> when the weather warms a little, it's -1 here in west Denver right
>> now.
>>
>
> First generation heated O2 sensor

Thanks. :)

From: Hachiroku ハチロク on
On Sun, 14 Dec 2008 17:19:47 -0600, Sarah Houston wrote:

> =?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno(a)e86.GTS> wrote
> :
>
>> On Sun, 14 Dec 2008 00:46:06 -0600, Sarah Houston wrote:
>>
>>>
>>> After doing some extensive reading, it began to come clear how the O2
>>> Sensor performance could be off, yet not be able to see any symptoms
>>> (other than lower gas mileage) with the tools I was using.
>>
>> Hmmm...are you really a girl?
>
> I didn't write that, it was at that site.
>
>> Where are you?
>> Can you replace transmissions and U-joints? ;)
>
> No, about all I do is my own plugs, dist caps, the easy top side stuff.
>
> Don't even mess with my own oil changes.

Shoot. You know, kinda like the ad: Seeking woman with bass boat; Object:
Matrimony. Please send picture of boat... ;)



From: Ray O on

"Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message
news:Xns9B74F359FBE50SntzldfrdSntzldfrdco(a)216.196.97.142...
<snipped>
>> First generation heated O2 sensor
>
> Thanks. :)
>
You're welcome!
--

Ray O
(correct punctuation to reply)


From: Sarah Houston on
=?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno(a)e86.GTS>
wrote :

> On Sun, 14 Dec 2008 17:19:47 -0600, Sarah Houston wrote:
>
>> =?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno(a)e86.GTS>
>> wrote
>> :
>>
>>> On Sun, 14 Dec 2008 00:46:06 -0600, Sarah Houston wrote:
>>>
>>>>
>>>> After doing some extensive reading, it began to come clear how the
>>>> O2 Sensor performance could be off, yet not be able to see any
>>>> symptoms (other than lower gas mileage) with the tools I was
>>>> using.
>>>
>>> Hmmm...are you really a girl?
>>
>> I didn't write that, it was at that site.
>>
>>> Where are you?
>>> Can you replace transmissions and U-joints? ;)
>>
>> No, about all I do is my own plugs, dist caps, the easy top side
>> stuff.
>>
>> Don't even mess with my own oil changes.
>
> Shoot. You know, kinda like the ad: Seeking woman with bass boat;
> Object: Matrimony. Please send picture of boat... ;)

:)