Error P0135 Sensor Heater Circuit Malfunction

My check engine light recently came on in my 1997 Toyota Avalon XLS
(101,000 miles). I took the car to Auto Zone to hook it up to the
computer and the error was P0135 Sensor Heater Circuit Malfunction Bank
1 Sensor 1. Is this a problem that I can live with without correcting?
Is this a problem that an engineer (electrical although I dont know
that much about the inner workings of the circuitry of my car) could
fix? Is this just an interchangable part that I could swap out?

Any help would be greatly appreciated. I have noticed over the last
few months that my car has a lot of trouble "going" in the morning and
almost dies when I back it up out of my garage if it has not been
driven in a while. Is this part of the Sensor Heater problem?

Thanks,
Stephen

<stephen.burks@gmail.com> wrote in message
news:1121883633.644095.155210@o13g2000cwo.googlegroups.com...[color=blue]
> My check engine light recently came on in my 1997 Toyota Avalon XLS
> (101,000 miles). I took the car to Auto Zone to hook it up to the
> computer and the error was P0135 Sensor Heater Circuit Malfunction Bank
> 1 Sensor 1. Is this a problem that I can live with without correcting?
> Is this a problem that an engineer (electrical although I dont know
> that much about the inner workings of the circuitry of my car) could
> fix? Is this just an interchangable part that I could swap out?
>
> Any help would be greatly appreciated. I have noticed over the last
> few months that my car has a lot of trouble "going" in the morning and
> almost dies when I back it up out of my garage if it has not been
> driven in a while. Is this part of the Sensor Heater problem?
>
> Thanks,
> Stephen
>[/color]

Error code P0135 is "O2 sensor heater circuit malfunction bank 1 sensor 1.
Automotive sensors are generally described by what they are supposed to
sense, i.e., oxygen, air flow, coolant temperature, etc.

Although I always recommend that someone check a component before checking
it, I seem to hear of problems with this sensor often enough that swapping
it out is probably not a bad bet.

Bank 1 sensor 1 will be in the exhaust manifold on the side of the engine
closest to the firewall. Reaching it is the biggest challenge, otherwise,
unsnap the connector, and righty tighty lefty loosey to remove and replace
the O2 sensor.
--
Ray O
correct the return address punctuation to reply

I can get a part like this at a typical car parts store, right? Thanks
for the quick reply.

<stephen.burks@gmail.com> wrote in message
news:1121885876.986285.35630@g49g2000cwa.googlegroups.com...[color=blue]
>I can get a part like this at a typical car parts store, right? Thanks
> for the quick reply.
>[/color]

Yes, you can get an O2 sensor at a typical auto parts store, although I
personally prefer genuine Toyota parts.
--
Ray O
correct the return address punctuation to reply

One more question concerning this. How will this sensor not
functioning properly affect my car?

One more thing...I was doing some research and I found that there are
oxygen sensors for before or after the calyltic converter. Do I need
to replace both? They are listed as 64$ or 130$. There is a large
difference in the prices of them. Besides the warranty, is there any
real difference in the mechanics of the two?

Thanks again,
Stephen

<stephen.burks@gmail.com> wrote in message
news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=blue]
> One more thing...I was doing some research and I found that there are
> oxygen sensors for before or after the calyltic converter. Do I need
> to replace both? They are listed as 64$ or 130$. There is a large
> difference in the prices of them. Besides the warranty, is there any
> real difference in the mechanics of the two?
>
> Thanks again,
> Stephen
>[/color]
Basically, the oxygen (O2) sensor measures the amount of oxygen in the
exhaust gas and reports the O2 levels back to the engine computer. The
computer uses the information to adjust the air/fuel mixture.

On systems with O2 sensors before and after the catalytic converter, the one
after the cat is monitoring whether the cat is doing its job or not.
Vehicles with an OBD II system use this setup. The OBD II diagnostic system
is primarily designed to control emissions.

An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
properly so a heated one has a heating element inside to get to this
temperature much more quickly than waiting to get heated by exhaust gases.
The quicker the O2 sensor gets to operating temperature, the sooner the
computer has the info it needs to reduce emissions.

The trouble code you mentioned means that the heating element in the sensor
isn't working so exhaust emissions may be too high. You may or may not
discern reduced engine performance.

You only need to replace the bad O2 sensor. There is no need to replace
ones that have not set a trouble code unless you have failed an emissions
test or notice poor performance and further testing points to a bad sensor.

I prefer OEM parts and I have heard complaints of relatively short life on
some aftermarket O2 sensors. for that reason, my recommendation is to use a
genuine Toyota sensor, even if it costs more than an aftermarket one. When
the aftermarket one is working properly, then functionally it is the same as
an OEM one. If immediate cost is an issue, then an aftermarket sensor
should work OK, at least for a while.
--
Ray O
correct the return address punctuation to reply

"Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
news:2743a$42dffd17$44a4a10d$14537@msgid.meganewsservers.com...[color=blue]
>
> <stephen.burks@gmail.com> wrote in message
> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=green]
>> One more thing...I was doing some research and I found that there are
>> oxygen sensors for before or after the calyltic converter. Do I need
>> to replace both? They are listed as 64$ or 130$. There is a large
>> difference in the prices of them. Besides the warranty, is there any
>> real difference in the mechanics of the two?
>>
>> Thanks again,
>> Stephen
>>[/color]
> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
> exhaust gas and reports the O2 levels back to the engine computer. The
> computer uses the information to adjust the air/fuel mixture.
>
> On systems with O2 sensors before and after the catalytic converter, the
> one after the cat is monitoring whether the cat is doing its job or not.
> Vehicles with an OBD II system use this setup. The OBD II diagnostic
> system is primarily designed to control emissions.
>
> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
> properly so a heated one has a heating element inside to get to this
> temperature much more quickly than waiting to get heated by exhaust gases.
> The quicker the O2 sensor gets to operating temperature, the sooner the
> computer has the info it needs to reduce emissions.
>
> The trouble code you mentioned means that the heating element in the
> sensor isn't working so exhaust emissions may be too high. You may or may
> not discern reduced engine performance.
>[/color]

To expound on this a bit, the code you are getting only means the heating
portion of the sensor has failed. If the sensor was not working, it can
throw the computer into "limp mode" or it can simply misread the fuel
mixture in the exhaust stream, and adjust the fuel in the intake
incorrectly. If this happens, the fuel mixture can be too rich, meaning you
consume more gas than you need to, and your fuel mileage will suffer as a
result.

If the car made lots of short trips, then the sensor would be cold, and the
mixture would probably be rich. If you started the car and made a long trip
before shutting the motor off, then the mixture would probably be OK, but it
would run rich early in the trip before the O2 sensor warmed up from the
exhaust gas.

The heating element is part of the sensor, so the corrective action is to
replace the sensor. The sensor screws into the exhaust system, much the same
as a spark plug screws into the head. There is a special wrench to use that
accomodates the wire in the sensor, but if your sensor is located in a spot
with ample room, you can get it out with a standard end-wrench. The special
wrench is a socket with a notch cut out so the wire doesn't get in the way.




[color=blue]
> You only need to replace the bad O2 sensor. There is no need to replace
> ones that have not set a trouble code unless you have failed an emissions
> test or notice poor performance and further testing points to a bad
> sensor.
>
> I prefer OEM parts and I have heard complaints of relatively short life on
> some aftermarket O2 sensors. for that reason, my recommendation is to use
> a genuine Toyota sensor, even if it costs more than an aftermarket one.
> When the aftermarket one is working properly, then functionally it is the
> same as an OEM one. If immediate cost is an issue, then an aftermarket
> sensor should work OK, at least for a while.[/color]

I'm not so married to OEM parts for this application as Ray is. My theory is
that exhaust gas isn't very complicated, and there are probably only three
of four companies in the entire universe that actually make these things
anyway. I wouldn't hesitate to use a Bosch or Autolite or other name-brand
O2 sensor. I suppose Ray has a valid point though, Toyota can have higher
quality standards for OEM parts than the aftermarket will demand. I am a
skeptic, and I don't think that Toyota will have a different quality
standard than the same part in the aftermarket. My guess is that Toyota uses
a NGK O2 Sensor, but I don't know that to be a fact.

As Ray points out, the OEM part isn't going to cost substantially more, but
it will offer a piece-of-mind quality that might be worth the cost.

"J Strickland" <spam@nospam.net> wrote in message
news:OYadnewgpKaqk33fRVn-2Q@ez2.net...[color=blue]
>
> "Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
> news:2743a$42dffd17$44a4a10d$14537@msgid.meganewsservers.com...[color=green]
>>
>> <stephen.burks@gmail.com> wrote in message
>> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=darkred]
>>> One more thing...I was doing some research and I found that there are
>>> oxygen sensors for before or after the calyltic converter. Do I need
>>> to replace both? They are listed as 64$ or 130$. There is a large
>>> difference in the prices of them. Besides the warranty, is there any
>>> real difference in the mechanics of the two?
>>>
>>> Thanks again,
>>> Stephen
>>>[/color]
>> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
>> exhaust gas and reports the O2 levels back to the engine computer. The
>> computer uses the information to adjust the air/fuel mixture.
>>
>> On systems with O2 sensors before and after the catalytic converter, the
>> one after the cat is monitoring whether the cat is doing its job or not.
>> Vehicles with an OBD II system use this setup. The OBD II diagnostic
>> system is primarily designed to control emissions.
>>
>> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
>> properly so a heated one has a heating element inside to get to this
>> temperature much more quickly than waiting to get heated by exhaust
>> gases. The quicker the O2 sensor gets to operating temperature, the
>> sooner the computer has the info it needs to reduce emissions.
>>
>> The trouble code you mentioned means that the heating element in the
>> sensor isn't working so exhaust emissions may be too high. You may or
>> may not discern reduced engine performance.
>>[/color]
>
> To expound on this a bit, the code you are getting only means the heating
> portion of the sensor has failed. If the sensor was not working, it can
> throw the computer into "limp mode" or it can simply misread the fuel
> mixture in the exhaust stream, and adjust the fuel in the intake
> incorrectly.[/color]

A failed O2 sensor will not put the computer into "limp" mode. If the
Electronic Control Unit ("ECU" detects a failed O2 sensor, it will
illuminate the Malfunction Indicator Light (MIL), commonly referred to as a
check engine light and go into open loop mode.
[color=blue]
>If this happens, the fuel mixture can be too rich, meaning you consume more
>gas than you need to, and your fuel mileage will suffer as a result.
>
> If the car made lots of short trips, then the sensor would be cold, and
> the mixture would probably be rich. If you started the car and made a long
> trip before shutting the motor off, then the mixture would probably be OK,
> but it would run rich early in the trip before the O2 sensor warmed up
> from the exhaust gas.
>[/color]

A malfunctioning O2 sensor or O2 sensor heater will not necessarily cause an
overly rich mixture, whether the trip is long or short. All it does is keep
the ECU in open loop longer.

[color=blue]
> The heating element is part of the sensor, so the corrective action is to
> replace the sensor. The sensor screws into the exhaust system, much the
> same as a spark plug screws into the head. There is a special wrench to
> use that accomodates the wire in the sensor, but if your sensor is located
> in a spot with ample room, you can get it out with a standard end-wrench.
> The special wrench is a socket with a notch cut out so the wire doesn't
> get in the way.
>
>[color=green]
>> You only need to replace the bad O2 sensor. There is no need to replace
>> ones that have not set a trouble code unless you have failed an emissions
>> test or notice poor performance and further testing points to a bad
>> sensor.
>>
>> I prefer OEM parts and I have heard complaints of relatively short life
>> on some aftermarket O2 sensors. for that reason, my recommendation is to
>> use a genuine Toyota sensor, even if it costs more than an aftermarket
>> one. When the aftermarket one is working properly, then functionally it
>> is the same as an OEM one. If immediate cost is an issue, then an
>> aftermarket sensor should work OK, at least for a while.[/color]
>
> I'm not so married to OEM parts for this application as Ray is. My theory
> is that exhaust gas isn't very complicated, and there are probably only
> three of four companies in the entire universe that actually make these
> things anyway.[/color]

For you, exhaust gas may not be complicated, but for automotive engineers,
it is pretty complicated. If it were easy for automotive engineers, every
vehicle would have nothing but C02 and H20 coming out the pipe a long time
ago.

I wouldn't hesitate to use a Bosch or Autolite or other name-brand[color=blue]
> O2 sensor. I suppose Ray has a valid point though, Toyota can have higher
> quality standards for OEM parts than the aftermarket will demand. I am a
> skeptic, and I don't think that Toyota will have a different quality
> standard than the same part in the aftermarket. My guess is that Toyota
> uses a NGK O2 Sensor, but I don't know that to be a fact.
>
> As Ray points out, the OEM part isn't going to cost substantially more,
> but it will offer a piece-of-mind quality that might be worth the cost.
>[/color]

A reason that O2 sensors deteriorate over time is that they are sticking
into the exhaust stream, gradually getting coated with the crud in the
exhaust. Enough crud builds up and the sensor can't sniff the O2 through
the crud.

As far as the reliability of the OEM vs. aftermarket, I'm just going by my
personal experience. On a friend's car, the original O2 sensor lasted
around 100k miles, the 2 aftermarket replacements lasted about 50k each, or
about half as long as the original one lasted. I have never replaced an O2
sensor in my personal vehicles so for me, the OEM O2 sensors have never
failed.
--
Ray O
correct the return address punctuation to reply

"Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
news:ce49$42e0161f$44a4a10d$16397@msgid.meganewsservers.com...[color=blue]
>
> "J Strickland" <spam@nospam.net> wrote in message
> news:OYadnewgpKaqk33fRVn-2Q@ez2.net...[color=green]
>>
>> "Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
>> news:2743a$42dffd17$44a4a10d$14537@msgid.meganewsservers.com...[color=darkred]
>>>
>>> <stephen.burks@gmail.com> wrote in message
>>> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...
>>>> One more thing...I was doing some research and I found that there are
>>>> oxygen sensors for before or after the calyltic converter. Do I need
>>>> to replace both? They are listed as 64$ or 130$. There is a large
>>>> difference in the prices of them. Besides the warranty, is there any
>>>> real difference in the mechanics of the two?
>>>>
>>>> Thanks again,
>>>> Stephen
>>>>
>>> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
>>> exhaust gas and reports the O2 levels back to the engine computer. The
>>> computer uses the information to adjust the air/fuel mixture.
>>>
>>> On systems with O2 sensors before and after the catalytic converter, the
>>> one after the cat is monitoring whether the cat is doing its job or not.
>>> Vehicles with an OBD II system use this setup. The OBD II diagnostic
>>> system is primarily designed to control emissions.
>>>
>>> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to
>>> operate properly so a heated one has a heating element inside to get to
>>> this temperature much more quickly than waiting to get heated by exhaust
>>> gases. The quicker the O2 sensor gets to operating temperature, the
>>> sooner the computer has the info it needs to reduce emissions.
>>>
>>> The trouble code you mentioned means that the heating element in the
>>> sensor isn't working so exhaust emissions may be too high. You may or
>>> may not discern reduced engine performance.
>>>[/color]
>>
>> To expound on this a bit, the code you are getting only means the heating
>> portion of the sensor has failed. If the sensor was not working, it can
>> throw the computer into "limp mode" or it can simply misread the fuel
>> mixture in the exhaust stream, and adjust the fuel in the intake
>> incorrectly.[/color]
>
> A failed O2 sensor will not put the computer into "limp" mode. If the
> Electronic Control Unit ("ECU" detects a failed O2 sensor, it will
> illuminate the Malfunction Indicator Light (MIL), commonly referred to as
> a check engine light and go into open loop mode.
>[color=green]
>>If this happens, the fuel mixture can be too rich, meaning you consume
>>more gas than you need to, and your fuel mileage will suffer as a result.
>>
>> If the car made lots of short trips, then the sensor would be cold, and
>> the mixture would probably be rich. If you started the car and made a
>> long trip before shutting the motor off, then the mixture would probably
>> be OK, but it would run rich early in the trip before the O2 sensor
>> warmed up from the exhaust gas.
>>[/color]
>
> A malfunctioning O2 sensor or O2 sensor heater will not necessarily cause
> an overly rich mixture, whether the trip is long or short. All it does is
> keep the ECU in open loop longer.
>
>[/color]

I guess I'm saying that Open Loop and Limp Mode are the same. You are saying
they are not.


[color=blue][color=green]
>> The heating element is part of the sensor, so the corrective action is to
>> replace the sensor. The sensor screws into the exhaust system, much the
>> same as a spark plug screws into the head. There is a special wrench to
>> use that accomodates the wire in the sensor, but if your sensor is
>> located in a spot with ample room, you can get it out with a standard
>> end-wrench. The special wrench is a socket with a notch cut out so the
>> wire doesn't get in the way.
>>
>>[color=darkred]
>>> You only need to replace the bad O2 sensor. There is no need to replace
>>> ones that have not set a trouble code unless you have failed an
>>> emissions test or notice poor performance and further testing points to
>>> a bad sensor.
>>>
>>> I prefer OEM parts and I have heard complaints of relatively short life
>>> on some aftermarket O2 sensors. for that reason, my recommendation is
>>> to use a genuine Toyota sensor, even if it costs more than an
>>> aftermarket one. When the aftermarket one is working properly, then
>>> functionally it is the same as an OEM one. If immediate cost is an
>>> issue, then an aftermarket sensor should work OK, at least for a while.[/color]
>>
>> I'm not so married to OEM parts for this application as Ray is. My theory
>> is that exhaust gas isn't very complicated, and there are probably only
>> three of four companies in the entire universe that actually make these
>> things anyway.[/color]
>
> For you, exhaust gas may not be complicated, but for automotive engineers,
> it is pretty complicated. If it were easy for automotive engineers, every
> vehicle would have nothing but C02 and H20 coming out the pipe a long time
> ago.
>[/color]

I didn't mean it is easy, as in it can be solved. I meant it's easy in that
all cars pretty much create the same gases that have to be analyzed and
adjusted. O2 sensors all work pretty much the same way, kind of like light
bulbs work the same way. They can work in varying ranges dependent on the
environment, but once the range is determined, the rest is pretty much the
same. There is little difference in a 15W light bulb and a 100W light bulb,
once it is determined by the engineer that a 15W or a 100W bulb is needed,
there isn't much difference in how the bulbs actually work. In that respect,
it isn't very complicated.

[color=blue]
> I wouldn't hesitate to use a Bosch or Autolite or other name-brand[color=green]
>> O2 sensor. I suppose Ray has a valid point though, Toyota can have higher
>> quality standards for OEM parts than the aftermarket will demand. I am a
>> skeptic, and I don't think that Toyota will have a different quality
>> standard than the same part in the aftermarket. My guess is that Toyota
>> uses a NGK O2 Sensor, but I don't know that to be a fact.
>>
>> As Ray points out, the OEM part isn't going to cost substantially more,
>> but it will offer a piece-of-mind quality that might be worth the cost.
>>[/color]
>
> A reason that O2 sensors deteriorate over time is that they are sticking
> into the exhaust stream, gradually getting coated with the crud in the
> exhaust. Enough crud builds up and the sensor can't sniff the O2 through
> the crud.
>
> As far as the reliability of the OEM vs. aftermarket, I'm just going by my
> personal experience. On a friend's car, the original O2 sensor lasted
> around 100k miles, the 2 aftermarket replacements lasted about 50k each,
> or about half as long as the original one lasted. I have never replaced
> an O2 sensor in my personal vehicles so for me, the OEM O2 sensors have
> never failed.[/color]


Again, I respect that view. I don't share it, but I see how you arrive at
it. I have only had one O2 sensor ever go bad, and the wires laid across the
exhaust system and cooked. You are in the business, and have a much larger
dataset to draw on.

"J Strickland" <spam@nospam.net> wrote in message
news:UtCdnRmso_U1hH3fRVn-vg@ez2.net...

<snip>
[color=blue][color=green]
>> A malfunctioning O2 sensor or O2 sensor heater will not necessarily cause
>> an overly rich mixture, whether the trip is long or short. All it does
>> is keep the ECU in open loop longer.
>>
>>[/color]
>
> I guess I'm saying that Open Loop and Limp Mode are the same. You are
> saying they are not.
>[/color]

Open loop is part of the normal operation of the vehicle, limp mode is not.

Under limp mode, the ECU fixes certain functions with no adjustment, like
air/fuel mixture and ignition timing. The vehicle will run very roughly in
limp mode.

<snip>
[color=blue][color=green][color=darkred]
>>> I'm not so married to OEM parts for this application as Ray is. My
>>> theory is that exhaust gas isn't very complicated, and there are
>>> probably only three of four companies in the entire universe that
>>> actually make these things anyway.[/color]
>>
>> For you, exhaust gas may not be complicated, but for automotive
>> engineers, it is pretty complicated. If it were easy for automotive
>> engineers, every vehicle would have nothing but C02 and H20 coming out
>> the pipe a long time ago.
>>[/color]
>
> I didn't mean it is easy, as in it can be solved. I meant it's easy in
> that all cars pretty much create the same gases that have to be analyzed
> and adjusted. O2 sensors all work pretty much the same way, kind of like
> light bulbs work the same way. They can work in varying ranges dependent
> on the environment, but once the range is determined, the rest is pretty
> much the same. There is little difference in a 15W light bulb and a 100W
> light bulb, once it is determined by the engineer that a 15W or a 100W
> bulb is needed, there isn't much difference in how the bulbs actually
> work. In that respect, it isn't very complicated.
>[/color]

I understood your original intent, sorry, I was just bustin' your chops!
It's the Mr. Miyagi in me.
[color=blue][color=green]
>> I wouldn't hesitate to use a Bosch or Autolite or other name-brand[color=darkred]
>>> O2 sensor. I suppose Ray has a valid point though, Toyota can have
>>> higher quality standards for OEM parts than the aftermarket will demand.
>>> I am a skeptic, and I don't think that Toyota will have a different
>>> quality standard than the same part in the aftermarket. My guess is that
>>> Toyota uses a NGK O2 Sensor, but I don't know that to be a fact.
>>>
>>> As Ray points out, the OEM part isn't going to cost substantially more,
>>> but it will offer a piece-of-mind quality that might be worth the cost.
>>>[/color]
>>
>> A reason that O2 sensors deteriorate over time is that they are sticking
>> into the exhaust stream, gradually getting coated with the crud in the
>> exhaust. Enough crud builds up and the sensor can't sniff the O2 through
>> the crud.
>>
>> As far as the reliability of the OEM vs. aftermarket, I'm just going by
>> my personal experience. On a friend's car, the original O2 sensor lasted
>> around 100k miles, the 2 aftermarket replacements lasted about 50k each,
>> or about half as long as the original one lasted. I have never replaced
>> an O2 sensor in my personal vehicles so for me, the OEM O2 sensors have
>> never failed.[/color]
>
>
> Again, I respect that view. I don't share it, but I see how you arrive at
> it. I have only had one O2 sensor ever go bad, and the wires laid across
> the exhaust system and cooked. You are in the business, and have a much
> larger dataset to draw on.[/color]

Some things to remember when working on Toyotas vs. German makes: - The
Germans seems to do things the opposite of everyone else. Remember using a
bolt to attach the wheels on a VW instead of studs and lug nuts like
everyone else?

Before Mercedes Benz bowed to consumer demand and offered tilt steering
wheels, their response when asked when they would offer one was "We spent
millions determining the optimal steering wheel angle - why would you want
to change it?"

Just remember Jeff-san:

Wax on,
Wax off
:-)
--
Ray O
correct the return address punctuation to reply

Ray O wrote:
[color=blue]
> <stephen.burks@gmail.com> wrote in message
> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=green]
> > One more thing...I was doing some research and I found that there are
> > oxygen sensors for before or after the calyltic converter. Do I need
> > to replace both? They are listed as 64$ or 130$. There is a large
> > difference in the prices of them. Besides the warranty, is there any
> > real difference in the mechanics of the two?
> >
> > Thanks again,
> > Stephen
> >[/color]
> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
> exhaust gas and reports the O2 levels back to the engine computer. The
> computer uses the information to adjust the air/fuel mixture.
>
> On systems with O2 sensors before and after the catalytic converter, the one
> after the cat is monitoring whether the cat is doing its job or not.
> Vehicles with an OBD II system use this setup. The OBD II diagnostic system
> is primarily designed to control emissions.
>
> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
> properly so a heated one has a heating element inside to get to this
> temperature much more quickly than waiting to get heated by exhaust gases.
> The quicker the O2 sensor gets to operating temperature, the sooner the
> computer has the info it needs to reduce emissions.
>
> The trouble code you mentioned means that the heating element in the sensor
> isn't working so exhaust emissions may be too high. You may or may not
> discern reduced engine performance.
>
> You only need to replace the bad O2 sensor. There is no need to replace
> ones that have not set a trouble code unless you have failed an emissions
> test or notice poor performance and further testing points to a bad sensor.
>
> I prefer OEM parts and I have heard complaints of relatively short life on
> some aftermarket O2 sensors. for that reason, my recommendation is to use a
> genuine Toyota sensor, even if it costs more than an aftermarket one. When
> the aftermarket one is working properly, then functionally it is the same as
> an OEM one. If immediate cost is an issue, then an aftermarket sensor
> should work OK, at least for a while.
> --
> Ray O
> correct the return address punctuation to reply[/color]

Could such a sensor be pulled from a junkyard car's exhaust system?

Lou

<Lou@GoForIt.net> wrote in message news:42E0244E.715668DA@optonline.net...[color=blue]
> Ray O wrote:
>[color=green]
>> <stephen.burks@gmail.com> wrote in message
>> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=darkred]
>> > One more thing...I was doing some research and I found that there are
>> > oxygen sensors for before or after the calyltic converter. Do I need
>> > to replace both? They are listed as 64$ or 130$. There is a large
>> > difference in the prices of them. Besides the warranty, is there any
>> > real difference in the mechanics of the two?
>> >
>> > Thanks again,
>> > Stephen
>> >[/color]
>> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
>> exhaust gas and reports the O2 levels back to the engine computer. The
>> computer uses the information to adjust the air/fuel mixture.
>>
>> On systems with O2 sensors before and after the catalytic converter, the
>> one
>> after the cat is monitoring whether the cat is doing its job or not.
>> Vehicles with an OBD II system use this setup. The OBD II diagnostic
>> system
>> is primarily designed to control emissions.
>>
>> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
>> properly so a heated one has a heating element inside to get to this
>> temperature much more quickly than waiting to get heated by exhaust
>> gases.
>> The quicker the O2 sensor gets to operating temperature, the sooner the
>> computer has the info it needs to reduce emissions.
>>
>> The trouble code you mentioned means that the heating element in the
>> sensor
>> isn't working so exhaust emissions may be too high. You may or may not
>> discern reduced engine performance.
>>
>> You only need to replace the bad O2 sensor. There is no need to replace
>> ones that have not set a trouble code unless you have failed an emissions
>> test or notice poor performance and further testing points to a bad
>> sensor.
>>
>> I prefer OEM parts and I have heard complaints of relatively short life
>> on
>> some aftermarket O2 sensors. for that reason, my recommendation is to
>> use a
>> genuine Toyota sensor, even if it costs more than an aftermarket one.
>> When
>> the aftermarket one is working properly, then functionally it is the same
>> as
>> an OEM one. If immediate cost is an issue, then an aftermarket sensor
>> should work OK, at least for a while.
>> --
>> Ray O
>> correct the return address punctuation to reply[/color]
>
> Could such a sensor be pulled from a junkyard car's exhaust system?
>
> Lou
>[/color]
Yes, it could. There is no way to tell what the remaining life is. I'm not
sure if the hassle is worth the cost savings.
--
Ray O
correct the return address punctuation to reply

"Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
news:363cb$42e02456$44a4a10d$17808@msgid.meganewsservers.com...[color=blue]
>
> "J Strickland" <spam@nospam.net> wrote in message
> news:UtCdnRmso_U1hH3fRVn-vg@ez2.net...
>
> <snip>
>[color=green][color=darkred]
>>> A malfunctioning O2 sensor or O2 sensor heater will not necessarily
>>> cause an overly rich mixture, whether the trip is long or short. All it
>>> does is keep the ECU in open loop longer.
>>>
>>>[/color]
>>
>> I guess I'm saying that Open Loop and Limp Mode are the same. You are
>> saying they are not.
>>[/color]
>
> Open loop is part of the normal operation of the vehicle, limp mode is
> not.
>
> Under limp mode, the ECU fixes certain functions with no adjustment, like
> air/fuel mixture and ignition timing. The vehicle will run very roughly
> in limp mode.
>[/color]

I didn't know that distinction. I was thinking open loop and limp were
essentially the same thing. Both would set the car to a setting that could
get it home. What happens in open loop that is different than limp?

<Lou@GoForIt.net> wrote in message news:42E0244E.715668DA@optonline.net...[color=blue]
> Ray O wrote:
>[color=green]
>> <stephen.burks@gmail.com> wrote in message
>> news:1121957233.457928.184030@z14g2000cwz.googlegroups.com...[color=darkred]
>> > One more thing...I was doing some research and I found that there are
>> > oxygen sensors for before or after the calyltic converter. Do I need
>> > to replace both? They are listed as 64$ or 130$. There is a large
>> > difference in the prices of them. Besides the warranty, is there any
>> > real difference in the mechanics of the two?
>> >
>> > Thanks again,
>> > Stephen
>> >[/color]
>> Basically, the oxygen (O2) sensor measures the amount of oxygen in the
>> exhaust gas and reports the O2 levels back to the engine computer. The
>> computer uses the information to adjust the air/fuel mixture.
>>
>> On systems with O2 sensors before and after the catalytic converter, the
>> one
>> after the cat is monitoring whether the cat is doing its job or not.
>> Vehicles with an OBD II system use this setup. The OBD II diagnostic
>> system
>> is primarily designed to control emissions.
>>
>> An O2 sensor needs to be heated to over 600 degrees Fahrenheit to operate
>> properly so a heated one has a heating element inside to get to this
>> temperature much more quickly than waiting to get heated by exhaust
>> gases.
>> The quicker the O2 sensor gets to operating temperature, the sooner the
>> computer has the info it needs to reduce emissions.
>>
>> The trouble code you mentioned means that the heating element in the
>> sensor
>> isn't working so exhaust emissions may be too high. You may or may not
>> discern reduced engine performance.
>>
>> You only need to replace the bad O2 sensor. There is no need to replace
>> ones that have not set a trouble code unless you have failed an emissions
>> test or notice poor performance and further testing points to a bad
>> sensor.
>>
>> I prefer OEM parts and I have heard complaints of relatively short life
>> on
>> some aftermarket O2 sensors. for that reason, my recommendation is to
>> use a
>> genuine Toyota sensor, even if it costs more than an aftermarket one.
>> When
>> the aftermarket one is working properly, then functionally it is the same
>> as
>> an OEM one. If immediate cost is an issue, then an aftermarket sensor
>> should work OK, at least for a while.
>> --
>> Ray O
>> correct the return address punctuation to reply[/color]
>
> Could such a sensor be pulled from a junkyard car's exhaust system?[/color]


Sure, but why? The junk yard is where onen goes for hard to find stuff, and
expensive stuff that seldom breaks and used parts will do the trick.

The O2 sensor is not expensive, it isn't hard to find, and a used one isn't
going to be any better than the one you are taking off. The O2 sensor is a
common consumable part, just like a spark plug, would you go to a junk yard
for spark plugs? I wouldn't. It's much easier to get them from the auto
parts store on the corner. Indeed, if I was going to get a used motor from
the junk yard, I'd put a new O2 sensor in it just to be sure I didn't have
to chase gremlins that came from the old one.