From: Ray O on 15 Dec 2008 00:35 "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 15 Dec 2008 01:55 "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 15 Dec 2008 16:18 On Sun, 14 Dec 2008 17:19:47 -0600, Sarah Houston wrote: > =?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno(a)e86.GTS> wrote > : > >> On Sun, 14 Dec 2008 00:46:06 -0600, Sarah Houston wrote: >> >>> >>> After doing some extensive reading, it began to come clear how the O2 >>> Sensor performance could be off, yet not be able to see any symptoms >>> (other than lower gas mileage) with the tools I was using. >> >> Hmmm...are you really a girl? > > I didn't write that, it was at that site. > >> Where are you? >> Can you replace transmissions and U-joints? ;) > > No, about all I do is my own plugs, dist caps, the easy top side stuff. > > Don't even mess with my own oil changes. Shoot. You know, kinda like the ad: Seeking woman with bass boat; Object: Matrimony. Please send picture of boat... ;)
From: Ray O on 15 Dec 2008 16:24 "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message news:Xns9B74F359FBE50SntzldfrdSntzldfrdco(a)216.196.97.142... <snipped> >> First generation heated O2 sensor > > Thanks. :) > You're welcome! -- Ray O (correct punctuation to reply)
From: Sarah Houston on 16 Dec 2008 01:46
=?iso-2022-jp?q?Hachiroku_=1B$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... ;) :) |