"oxygen sensor"

[askb]

Jaka jest jego rola w pojezdzie ?
Jaki wplyw na stan silnika moze miec sygnalizowanie przez komp.
nieprawidlowosci w dzialaniu sensora/ow / ?
Ktos moze podzielic sie wiadomosciami ?

Pzdr. - dzieki za odpowiedz.

[Gość: altimat]

askb napisał:

> Jaka jest jego rola w pojezdzie ?
> Jaki wplyw na stan silnika moze miec sygnalizowanie przez komp.
> nieprawidlowosci w dzialaniu sensora/ow / ?
> Ktos moze podzielic sie wiadomosciami ?
>
> Pzdr. - dzieki za odpowiedz.
efektem moze byc zla emisja spalin oraz mozesz stracic katalizator

[Gość: altimat]

From Bosch "REPORTER Written by Technicians for Technicians," October 1998:

OXYGEN SENSORS: THEIR KEY ROLE IN REDUCING EXHAUST EMISSIONS

Automotive exhaust emissions are everyone's concern because we all breathe the
same air. Fifty percent of Americans live in areas which exceed national clean
air standards. Reducing tailpipe emissions, therefore, is a top priority in the
effort to fight air pollution.

In 1976, Bosch introduced what would eventually become one of the most
important technologies for reducing exhaust emissions: the oxygen sensor. By
1996, Bosch had produced its 100 millionth oxygen sensor. Today, Bosch oxygen
sensors are original equipment on a wide variety of European, Asian and
domestic vehicles and are the No. 1 best selling brand in the aftermarket.

Oxygen sensors have been standard equipment on passenger car and light truck
engines since 1980-81/ Most such vehicles have one or two oxygen sensors (two
are typically used on selected V6 and V8 engines starting in the late 80s).
Since the introduction of Onboard Diagnostics II (OBD II) in 1995-96, the
number of oxygen sensors per vehicle has doubled (the extra sensors are used
downstream of the catalytic converter to monitor its operating efficiency).
Yet, as important as oxygen sensors are today, few motorists are even aware of
their presence - let alone the key role oxygen sensors play in engine
performance and reducing pollution. One survey found that 99.7% of all
consumers did not know their vehicle had an oxygen sensor!

HOW THE O2 SENSOR FIGHTS POLLUTION

Originally called a "Lambda sensor" when it was first used in fuel-injection
European applications, the oxygen sensor monitors the level of oxygen (O2) in
the exhaust so an onboard computer can regulate the air/fuel mixture to reduce
emissions. The sensor is mounted in the exhaust manifold and generates a
voltage signal proportional to the amount of oxygen in the exhaust. The sensing
element on 99% of all oxygen sensors in use is a zirconium ceramic bulb coated
on both sides with a thin layer of platinum. The outside of the bulb is exposed
to the hot exhaust gases, while the inside of the bulb is vented internally
through the sensor body or wiring to the outside atmosphere.

When the air/fuel mixture is rich and there is little O2 in the exhaust, the
difference in oxygen levels across the sensing element generates a voltage
through the sensor's platinum electrodes: typically 0.8 to 0.9 volts. When the
air/fuel mixture is lean and there is more oxygen in the exhaust, the sensor's
voltage drops to 0.1 to 0.3 volts. When the air/fuel mixture is perfectly
balanced and combustion is cleanest, the sensor's output voltage is around 0.45
volts.

The oxygen sensor's voltage signal is monitored by the onboard engine
management computer to regulate the fuel mixture. When the computer sees a rich
signal (high voltage) from the O2 sensor, it commands the fuel mixture to go
lean. When the computer receives a lean signal (low voltage) from the O2
sensor, it commands the fuel mixture to go rich. Cycling back and forth from
rich to lean averages out the overall air/fuel mixture to minimize emissions
and to help the catalytic converter operate at peak efficiency (which is
necessary to reduce hydrocarbon (HC), carbon monoxide (CO) and oxides of
nitrogen (NOX) levels even further).

The speed with which the oxygen sensor reacts to oxygen changes in the exhaust
is very important for accurate fuel control, peak fuel economy, and low
emissions. The air/fuel mixture in an older carbureted engine doesn't change as
quickly as that in a throttle body fuel-injected application, so response time
is less critical. But, in newer engines with multipoint fuel injection, the
air/fuel mixture can change extremely fast, requiring a very quick response
from the o2 sensor.

SENSOR AGING

Nothing lasts forever, and oxygen sensors are no exception. As an oxygen
sensor, 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 notice 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.

SENSOR FAILURES

The normal aging process will eventually cause the oxygen sensor to fail.
However, the sensor, may also fail prematurely if it becomes contaminated with
lead from leaded gasoline, phosphorous from excessive oil consumption, or
silicone from internal coolant leaks or using silicone sprays or gasket sealers
on the engine. Environmental factors such as road splash, salt, oil, and dirt
can also cause a sensor to fail, as can mechanical stress or mishandling.

A dead sensor will prevent the onboard computer from making the necessary
air/fuel corrections, causing the air/fuel mixture to run rich in the "open
loop" mode f operation, resulting in much higher fuel consumption and emissions.

An additional consequence of an O2 sensor failure may be damage to the
catalytic converter. A rich operating condition causes the converter to run
hotter than normal. If the converter gets hot enough, the catalyst substrate
inside may actually melt forming a partial or complete blockage. The result can
be a drastic drop in highway performance or stalling because of a buildup of
backpressure in the exhaust system.

WEEDING OUT THE BAD ONES

Although some vehicles have an oxygen sensor "reminder" light to alert the
driver when it is time to check the oxygen sensor, most do not. So, unless
there's a noticeable driveability problem or a "Check Engine" light on, most
motorists have no way of knowing if their oxygen sensor is functioning properly
or not.

The growth of emissions testing nationwide is changing that, along with the
introduction of new "enhanced" emissions testing programs that simulate real
world driving conditions while emissions are being measured. The latest is
proving to be very effective at catching emissions problems that formerly
escaped detection.

According to a study conducted by Sierra Research, Inc., in 1996, oxygen sensor
failure is the "single greatest source of excessive emissions for fuel-injected
vehicles" and the second most significant cause of high emissions in carbureted
engines.

The U.S. Environmental Protection Agency (EPA) and the California Air Resource
Board (CARB) have found that oxygen sensor replacement was required on 42-58%
of all vehicles that were subjected to an emissions check and found to be
emitting high level s of hydrocarbons (HC) or Carbon monoxide (CO). Checking
the operation of the oxygen sensor and the feedback system, therefore, should
always be a priority anytime a vehicle fails an emissions test due to high HC
or CO.

Sensor performance can be checked by reading the sensor's output voltage to
make sure it corresponds with the air/fuel mixture (low when lean, high when
rich). The voltage signal can also be displayed as a waveform on an
oscilloscope to make sure the signal is changing back and forth from rich to
lean and is responding quickly enough to changes in the air/fuel ratio

O2 SENSOR REPLACEMENT FOR PREVENTATIVE MAINTENANCE

To minimize the consequences of normal aging, Bosch recommends oxygen sensor
replacement for preventative maintenance at the following intervals:

Unheated O2 s

[askb]

"altimat" dziekuje za podpowiedz, wiem co mam robic!
- where did find it ?

SA

[Gość: altimat]

askb napisał:

> "altimat" dziekuje za podpowiedz, wiem co mam robic!
> - where did find it ?
>
> SA
www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=oxygen+sensor+problem&btnG=Google+Search

[Gość: lrd]

to cos jest przy kolektorze wydechowym, podlaczone do elekt regulacji
mieszanki. w efekcie moze dawac za bogata lub za uboga. Najwiekszy problem to
test spalin, za duzo hc wydala. lampka to moze byc zwykly rem, po prostu
przypomina o wymianie, najczesciej zapala sie po przejechaniu ok 90kmil, co
wcale nie znaczy, ze sensor jest dupniety. Z wylaczeniem kontrolki moze byc
problem, zmiana sensora automatycznie nie wylacza swiatelka, pisza, zeby do
dealera jechac. osobiscie olalem, idzie przywyknac.

[Gość: altimat]

Gość portalu: lrd napisał:

> to cos jest przy kolektorze wydechowym, podlaczone do elekt regulacji
> mieszanki. w efekcie moze dawac za bogata lub za uboga. Najwiekszy problem to
> test spalin, za duzo hc wydala. lampka to moze byc zwykly rem, po prostu
> przypomina o wymianie, najczesciej zapala sie po przejechaniu ok 90kmil, co
> wcale nie znaczy, ze sensor jest dupniety. Z wylaczeniem kontrolki moze byc
> problem, zmiana sensora automatycznie nie wylacza swiatelka, pisza, zeby do
> dealera jechac. osobiscie olalem, idzie przywyknac.
zgadzam sie nie trzeba sie tym przejmowac-ale jesli naprawde sensor jest
uszkodzony to beda duze problemy z mieszanka ,ekonomia oraz osiagami.a jak
dojdzie do tego strata katalizatora to zycze powodzenia przy nastepnej
inspekcji.pzdr

[Gość: lrd]

Gość portalu: altimat napisał:


> zgadzam sie nie trzeba sie tym przejmowac-ale jesli naprawde sensor jest
> uszkodzony to beda duze problemy z mieszanka ,ekonomia oraz osiagami.a jak
> dojdzie do tego strata katalizatora to zycze powodzenia przy nastepnej
> inspekcji.pzdr

Jak najbardziej, spytalem sie jednego auto ghuru, on stwierdzil, ze ten sensor
z reguly sie nie psuje , niektore auta wogole nie maja kontrolki.pzdr.

[Gość: altimat]

Gość portalu: lrd napisał:

> Gość portalu: altimat napisał:
>
>
> > zgadzam sie nie trzeba sie tym przejmowac-ale jesli naprawde sensor jest
> > uszkodzony to beda duze problemy z mieszanka ,ekonomia oraz osiagami.a ja
> k
> > dojdzie do tego strata katalizatora to zycze powodzenia przy nastepnej
> > inspekcji.pzdr
>
> Jak najbardziej, spytalem sie jednego auto ghuru, on stwierdzil, ze ten
sensor
> z reguly sie nie psuje , niektore auta wogole nie maja kontrolki.pzdr.
mialem kilka lat temu problem w vw passat,spadly osiagi ,zwiekszylo sie zuzycie
paliwa.powod -uszkodzony oxygen sensor.szukalem gdzie mozna go kupic
najtaniej,no i znalazlem. ale podczas wymiany zobaczylem ze oryginalny sensor
mial 3 wychodzace z niego przewody natomiast nowy mial tylko dwa...ale dzieki
znajomosci pownego czlowieka ktory pracowal w serwisie vw wymienilem go na
odpowiedni bez zadnej oplaty:-)) (normalna cena u dealera to
270usd....hehehehe)

[Gość: Michal]

Zadko kiedy ten sensor nawala.Jezeli sklad spalin wykazuje za duza zawartosc
oxygenu to wiemy ze jest wsyssane falszywe poietrze po stronie ssacej motoru
lub dziurawy uklad wydechowy.Tutaj auta z nieprawidlowoscia wskazania ilosci
oxygenu w analizie spalin ,nie maja szans aby uzyskac zatwierdzona kontrole
roczna.Najczesciej z moich obserwacji zauwazylem ten problem wystepujacy w
modelach BMW seri 500.
Pzdr.Michal

Zmienialem sensor samodzielnie

[Gość: Marek]

- Kupilem nowy Bosha za $20
- poczekalem az samochod ostygnie (po nocy)
- wlaczylem silnik na pare minut
- w czasie gdy chodzil probowalem obluzowac sensor - to jedyna mozliwosc -
zeby sie kolektor nagrzal a obudowa nie - inaczej nie wyjdzie
- zgasilem silnik, wykrecilem bydlaka, wkrecilem nowy i podlaczylem - w teorii
potrzebny jest specjalny klucz (z dziurka na kabelek) ale jakos mi sie to
zwyklym oczkowym udalo. Aha - warto nasmarowac gwint specjalnym smarem do
kolektorow wydechowych - w przyszlosci bedzie latwiej zmienic.

Zauwazalne roznice:
- na nastepnym przegladzie mial troszke lepsze parametry, choc poprzednie byly
w normie
- spalanie troszeczke spadlo, ale to moze byc autosugestia
- bylem o $20 lzejszy + bogatszy o doswiadczenia + pare poparzen

P.S. Wymiana sensora to banal w 4-ro cylindrowcu i ciezka praca w V6 -
skurczybyk jest niedostepny.

[Gość: altimat]

Gość portalu: Marek napisał(a):

> - Kupilem nowy Bosha za $20
> - poczekalem az samochod ostygnie (po nocy)
> - wlaczylem silnik na pare minut
> - w czasie gdy chodzil probowalem obluzowac sensor - to jedyna mozliwosc -
> zeby sie kolektor nagrzal a obudowa nie - inaczej nie wyjdzie
> - zgasilem silnik, wykrecilem bydlaka, wkrecilem nowy i podlaczylem - w
teorii
> potrzebny jest specjalny klucz (z dziurka na kabelek) ale jakos mi sie to
> zwyklym oczkowym udalo. Aha - warto nasmarowac gwint specjalnym smarem do
> kolektorow wydechowych - w przyszlosci bedzie latwiej zmienic.
>
> Zauwazalne roznice:
> - na nastepnym przegladzie mial troszke lepsze parametry, choc poprzednie
byly
> w normie
> - spalanie troszeczke spadlo, ale to moze byc autosugestia
> - bylem o $20 lzejszy + bogatszy o doswiadczenia + pare poparzen
>
> P.S. Wymiana sensora to banal w 4-ro cylindrowcu i ciezka praca w V6 -
> skurczybyk jest niedostepny.
hehehe sprobuj wymienic sensor w vw passat 2.0 16v 1990-1993.szybko zmienisz
zdanie jak bedziesz musial rozebrac uklad wydechowy.pzdr

'oxygen sensor' zwyle sondą Lambda sie zowie

[darr.darek]