O2 sensors for '97 328

I have a 1997 328iC that is throwing catalytic converter codes along
with O2 sensor codes. Both me & the local converter expert suspect the problem
is actually more the O2 sensors than the converters, so I'm going to try
replacing them first. The problem is that BMW wants $200 + each for 4 of 'em!
That makes the sensors worth over $800!
Does anyone know where I can find some after market O2 sensors at a
reasonable price?
-

Jinks ('86FXRS, '07 FLTR)
#64
Remember, "No good deed goes unpunished"

On Thu, 07 Feb 2008 10:10:54 -0500, Jinks >
wrote:

> I have a 1997 328iC that is throwing catalytic converter codes along
>with O2 sensor codes. Both me & the local converter expert suspect the problem
>is actually more the O2 sensors than the converters, so I'm going to try
>replacing them first. The problem is that BMW wants $200 + each for 4 of 'em!
>That makes the sensors worth over $800!
> Does anyone know where I can find some after market O2 sensors at a
>reasonable price?
>-
>
>Jinks ('86FXRS, '07 FLTR)
>#64
>Remember, "No good deed goes unpunished"

You can get replacement sensors from just about any well stocked parts
store. You can get them without the BMW dedicated connector for
approximately $50-70 or with the connector for around $100.00 a piece.
If yours have never been replaced it is a past due maintenance item.
The general consensus is about 100K miles before replacement but they
do deteriorate with time. They can be tough to remove but a little
heating from a torch works wonders.

RJD

Jinks > wrote:
> I have a 1997 328iC that is throwing catalytic converter codes along
>with O2 sensor codes. Both me & the local converter expert suspect the problem
>is actually more the O2 sensors than the converters, so I'm going to try
>replacing them first. The problem is that BMW wants $200 + each for 4 of 'em!
>That makes the sensors worth over $800!
> Does anyone know where I can find some after market O2 sensors at a
>reasonable price?

NAPA will sell you some with the BMW connector, or some without the BMW
connector. If you buy the ones without the connector, solder and use
heatshrink on the wires chopped off of the old sensor. Don't even think
about using crimp connectors. If you use the ones with the connector already
on, they will cost twice as much but save you some time.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" > wrote in message
...
> Jinks > wrote:
>> I have a 1997 328iC that is throwing catalytic converter codes along
>>with O2 sensor codes. Both me & the local converter expert suspect the
>>problem
>>is actually more the O2 sensors than the converters, so I'm going to try
>>replacing them first. The problem is that BMW wants $200 + each for 4 of
>>'em!
>>That makes the sensors worth over $800!
>> Does anyone know where I can find some after market O2 sensors at a
>>reasonable price?
>
> NAPA will sell you some with the BMW connector, or some without the BMW
> connector. If you buy the ones without the connector, solder and use
> heatshrink on the wires chopped off of the old sensor. Don't even think
> about using crimp connectors. If you use the ones with the connector
> already
> on, they will cost twice as much but save you some time.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."
And, it is likely that the only ones that need to be replaced are those
upstream from the converter. The exhaust gas is quite a bit cooler after it
leaves the converter.
But, of course, a converter expert should realize this.
Jim

The CODE tells you which sensor is flaky.

There is a code for each Bank 1, Sensors 1 & 2, and for each, Bank 2,
Sensors 1 & 2.

Bank 1 Sensor 1 is the bank that contains exhaust from Cylinder 1, Bank 1
Sensor 2 contains the exhaust from the other three cylinders. Bank 2, Sensor
1 is the CAT that has processed exhaust from the pipe that contains exhaust
from Cylinder 1, Bank 2, Sensor 2 is the CAT that contains exhaust from the
other three cylilnders.

The CODE will tell you specifically which sensor is tossing up an error.
Give us the Code you are getting, and we can tell you which sensor is toast.

You can extract the code(s) with a OBD II scan tool, there is no need for
any specialized BMW tools. The OBD II data port lives along the bottom edge
of the dash board, either clearly visible OR hidden behind a small cover
that is clearly marked -- I believe BMW puts the port behind a small cover
and marks it as the data port. (The OBD II spec. requires the data port to
be easy to find, so you do not need to spend more than about 5 seconds
looking for it. Start your search near where your left leg rests while you
are driving.)

The Code for the Bank 1 sensors can be MALFUNCTION, TOO RICH, or TOO THIN,
(3 separate codes, one for each condition) or a Code related to the failure
of a heater that lives inside of the sensor itself. I forget the Code
options for the Bank 2 sensors, but they will translate to the CAT being
ineffective. There is a chance the CAT is dead, but a far better chance that
the sensor is bad. I have never had a CAT go bad in all my years of driving
cars with CATs in them. That is not to say that a CAT can not fail because
they can, but it is rare and under normal circumstances the owner/operator
of the vehicle has introduced fuel that is not suitable. (One must search
out unsutiable fuel, so the odds of this are very low and the effect is very
rapid so you would remember the event it it occurred.)

There can be multiple codes for any sensor, so a problem can percolate
through the computer in different ways. If you have a code for Bank 1 Sensor
1 and Bank 2 Sensor 2, odds favor only one of them being bad, and the other
reporting an out of spec condition that comes from the first in the stream
not working right. If Bank 1 Sensor 1 mis-detects the fuel mixture, and
adjusts the Fuel Injector Timing to cause more or less fule to be delivered,
the result can be that what flows past Bank 1 Sensor 2 is out of spec. In
this instance Bank 1 Sensor 2 is okay, and only Bank 1 Sensor 1 is giving
you trouble. If Bank 2 Sensor 1 (or Sensor 2) is throwing a fault in
isolation, then the sensors at Bank 1, Sensor 1 and 2 are working okay and
do not need attention.

Basically, replace the sensor closest to the engine (as the exhaust flows)
first to see if it resolves a false report from the next sensor downstream.
If the downstream sensor is throwing a code, but the upstream sensor is not,
then do not replace the upstream sensor.

"Scott Dorsey" > wrote in message
...
> Jinks > wrote:
>> I have a 1997 328iC that is throwing catalytic converter codes along
>>with O2 sensor codes. Both me & the local converter expert suspect the
>>problem
>>is actually more the O2 sensors than the converters, so I'm going to try
>>replacing them first. The problem is that BMW wants $200 + each for 4 of
>>'em!
>>That makes the sensors worth over $800!
>> Does anyone know where I can find some after market O2 sensors at a
>>reasonable price?
>
> NAPA will sell you some with the BMW connector, or some without the BMW
> connector. If you buy the ones without the connector, solder and use
> heatshrink on the wires chopped off of the old sensor. Don't even think
> about using crimp connectors. If you use the ones with the connector
> already
> on, they will cost twice as much but save you some time.
> --scott
> --


What Scott said ....

The caveat being, spend the money and buy a sensor with the connector
already attached. The single biggest reason for failure of a repair like
this is that the splice job went south. Do yourself a favor and buy the
sensor with the connector attached at the factory. I like the Bosch sensors,
by the way.

On Thu, 07 Feb 2008 17:03:08 GMT, "Jeff Strickland" > wrote:

>The CODE tells you which sensor is flaky.
>
>There is a code for each Bank 1, Sensors 1 & 2, and for each, Bank 2,
>Sensors 1 & 2.
>
>Bank 1 Sensor 1 is the bank that contains exhaust from Cylinder 1, Bank 1
>Sensor 2 contains the exhaust from the other three cylinders. Bank 2, Sensor
>1 is the CAT that has processed exhaust from the pipe that contains exhaust
>from Cylinder 1, Bank 2, Sensor 2 is the CAT that contains exhaust from the
>other three cylilnders.
>
>The CODE will tell you specifically which sensor is tossing up an error.
>Give us the Code you are getting, and we can tell you which sensor is toast.
>
>You can extract the code(s) with a OBD II scan tool, there is no need for
>any specialized BMW tools. The OBD II data port lives along the bottom edge
>of the dash board, either clearly visible OR hidden behind a small cover
>that is clearly marked -- I believe BMW puts the port behind a small cover
>and marks it as the data port. (The OBD II spec. requires the data port to
>be easy to find, so you do not need to spend more than about 5 seconds
>looking for it. Start your search near where your left leg rests while you
>are driving.)
>
>The Code for the Bank 1 sensors can be MALFUNCTION, TOO RICH, or TOO THIN,
>(3 separate codes, one for each condition) or a Code related to the failure
>of a heater that lives inside of the sensor itself. I forget the Code
>options for the Bank 2 sensors, but they will translate to the CAT being
>ineffective. There is a chance the CAT is dead, but a far better chance that
>the sensor is bad. I have never had a CAT go bad in all my years of driving
>cars with CATs in them. That is not to say that a CAT can not fail because
>they can, but it is rare and under normal circumstances the owner/operator
>of the vehicle has introduced fuel that is not suitable. (One must search
>out unsutiable fuel, so the odds of this are very low and the effect is very
>rapid so you would remember the event it it occurred.)
>
>There can be multiple codes for any sensor, so a problem can percolate
>through the computer in different ways. If you have a code for Bank 1 Sensor
>1 and Bank 2 Sensor 2, odds favor only one of them being bad, and the other
>reporting an out of spec condition that comes from the first in the stream
>not working right. If Bank 1 Sensor 1 mis-detects the fuel mixture, and
>adjusts the Fuel Injector Timing to cause more or less fule to be delivered,
>the result can be that what flows past Bank 1 Sensor 2 is out of spec. In
>this instance Bank 1 Sensor 2 is okay, and only Bank 1 Sensor 1 is giving
>you trouble. If Bank 2 Sensor 1 (or Sensor 2) is throwing a fault in
>isolation, then the sensors at Bank 1, Sensor 1 and 2 are working okay and
>do not need attention.
>
>Basically, replace the sensor closest to the engine (as the exhaust flows)
>first to see if it resolves a false report from the next sensor downstream.
>If the downstream sensor is throwing a code, but the upstream sensor is not,
>then do not replace the upstream sensor.

Jeff,
Sorry for not snippin' any of your reply, but I didn't want to miss
quote anything.
I think I followed most of what you wrote except for the second
paragraph about Bank/sensor/cylinder relationship. It appears to me that you
are talkin' about a 4 cylinder (318) rather than the 6 in my 328. Am I correct
or have I misunderstood?

If it's any help the codes it's throwin' are as follows:

233 = Cat. sys efficiency Bank 1

202 = Lambda control stop Bank 1

203 = Lambda control stop Bank 2

234 = Cat. sys efficiency Bank 2

I appreciate all of you folks quick replies, help, & training. Thank
You!
-

Jinks ('86FXRS, '07 FLTR)
#64
Remember, "No good deed goes unpunished"

"RJD" > wrote in message
news
> On Thu, 07 Feb 2008 10:10:54 -0500, Jinks >
> wrote:
>
>> I have a 1997 328iC that is throwing catalytic converter codes along
>>with O2 sensor codes. Both me & the local converter expert suspect the
>>problem
>>is actually more the O2 sensors than the converters, so I'm going to try
>>replacing them first. The problem is that BMW wants $200 + each for 4 of
>>'em!
>>That makes the sensors worth over $800!
>> Does anyone know where I can find some after market O2 sensors at a
>>reasonable price?
>>-
>>
>>Jinks ('86FXRS, '07 FLTR)
>>#64
>>Remember, "No good deed goes unpunished"
>
> You can get replacement sensors from just about any well stocked parts
> store. You can get them without the BMW dedicated connector for
> approximately $50-70 or with the connector for around $100.00 a piece.
> If yours have never been replaced it is a past due maintenance item.
> The general consensus is about 100K miles before replacement but they
> do deteriorate with time. They can be tough to remove but a little
> heating from a torch works wonders.

You can also approach the replacement as a phased effort. The sensors
upstream of the converter are the more important and when they fail, your
ECU will tend to overrichen the fuel mixture and impact mileage. Replace
them first, reset the OBD and see if that solves all or most of your
problems. If not, then pursue the rear pair.

R / John

"Jinks" > wrote in message
...
> On Thu, 07 Feb 2008 17:03:08 GMT, "Jeff Strickland" >
> wrote:
>
>>The CODE tells you which sensor is flaky.
>>
>>There is a code for each Bank 1, Sensors 1 & 2, and for each, Bank 2,
>>Sensors 1 & 2.
>>
>>Bank 1 Sensor 1 is the bank that contains exhaust from Cylinder 1, Bank 1
>>Sensor 2 contains the exhaust from the other three cylinders. Bank 2,
>>Sensor
>>1 is the CAT that has processed exhaust from the pipe that contains
>>exhaust
>>from Cylinder 1, Bank 2, Sensor 2 is the CAT that contains exhaust from
>>the
>>other three cylilnders.
>>
>>The CODE will tell you specifically which sensor is tossing up an error.
>>Give us the Code you are getting, and we can tell you which sensor is
>>toast.
>>
>>You can extract the code(s) with a OBD II scan tool, there is no need for
>>any specialized BMW tools. The OBD II data port lives along the bottom
>>edge
>>of the dash board, either clearly visible OR hidden behind a small cover
>>that is clearly marked -- I believe BMW puts the port behind a small cover
>>and marks it as the data port. (The OBD II spec. requires the data port to
>>be easy to find, so you do not need to spend more than about 5 seconds
>>looking for it. Start your search near where your left leg rests while you
>>are driving.)
>>
>>The Code for the Bank 1 sensors can be MALFUNCTION, TOO RICH, or TOO THIN,
>>(3 separate codes, one for each condition) or a Code related to the
>>failure
>>of a heater that lives inside of the sensor itself. I forget the Code
>>options for the Bank 2 sensors, but they will translate to the CAT being
>>ineffective. There is a chance the CAT is dead, but a far better chance
>>that
>>the sensor is bad. I have never had a CAT go bad in all my years of
>>driving
>>cars with CATs in them. That is not to say that a CAT can not fail because
>>they can, but it is rare and under normal circumstances the owner/operator
>>of the vehicle has introduced fuel that is not suitable. (One must search
>>out unsutiable fuel, so the odds of this are very low and the effect is
>>very
>>rapid so you would remember the event it it occurred.)
>>
>>There can be multiple codes for any sensor, so a problem can percolate
>>through the computer in different ways. If you have a code for Bank 1
>>Sensor
>>1 and Bank 2 Sensor 2, odds favor only one of them being bad, and the
>>other
>>reporting an out of spec condition that comes from the first in the stream
>>not working right. If Bank 1 Sensor 1 mis-detects the fuel mixture, and
>>adjusts the Fuel Injector Timing to cause more or less fule to be
>>delivered,
>>the result can be that what flows past Bank 1 Sensor 2 is out of spec. In
>>this instance Bank 1 Sensor 2 is okay, and only Bank 1 Sensor 1 is giving
>>you trouble. If Bank 2 Sensor 1 (or Sensor 2) is throwing a fault in
>>isolation, then the sensors at Bank 1, Sensor 1 and 2 are working okay and
>>do not need attention.
>>
>>Basically, replace the sensor closest to the engine (as the exhaust flows)
>>first to see if it resolves a false report from the next sensor
>>downstream.
>>If the downstream sensor is throwing a code, but the upstream sensor is
>>not,
>>then do not replace the upstream sensor.
>
> Jeff,
> Sorry for not snippin' any of your reply, but I didn't want to miss
> quote anything.
> I think I followed most of what you wrote except for the second
> paragraph about Bank/sensor/cylinder relationship. It appears to me that
> you
> are talkin' about a 4 cylinder (318) rather than the 6 in my 328. Am I
> correct
> or have I misunderstood?
>

I think you misunderstood. The exhaust header/manifold is split, there are
two sets of three tubes that collect the exhaust from the cylinders. Bank 1
Sensor 1 is mounted to the exhaust manifold that connects to Cyl #1. I don't
recall which other cylinders it connects to, but it really doesn't matter
for this discussion. Bank 1 Sensor 1 sniffs the exhaust coming from the
portion of the exhaust that contains Cyl. 1, Bank 2 Sensor 2 sniffs exhaust
that comes from the remaining bank. (Bank is a poor term because the motor
is an inline and Bank generally refers to the cylinder heads on a V-motor.
Having said that, bank is all we have, and the exhaust manifold is split so
that it collects from two sets of three cylinders so the term works, if a
bit inelegant.)



> If it's any help the codes it's throwin' are as follows:
>

Proper etiquette is to give the full code, P0233, P0202, P0203, P0234. In
the instance where the codes are all in the same family, you can use the
shorthand, P0202, 203, 233, and 234. You did okay, but there could be a
P1202, and then your use of only the last 3 digits could be misleading.

I'm not sure where you got your information from, but the codes you gave me
are completely different from the description.

Try this link,
http://autorepair.about.com/od/obdco..._1996_year.htm



> 233 = Cat. sys efficiency Bank 1
>
> 202 = Lambda control stop Bank 1
>
> 203 = Lambda control stop Bank 2
>
> 234 = Cat. sys efficiency Bank 2
>

Given this information -- which I think is wrong but for the sake of
example, I'm going to go with it for the moment -- I would replace something
upstream from the sensors. Frankly, I'm not sure what to replace, but here
is my theory.

The CAT effeciency codes say that the crap coming out of the CAT is not
within spec, therefore the CAT is bad or the sensors are bad. BUT, the
Lambda sensors up stream are also reporting the contenst of the exhaust as
being out of spec. This means that the crap GOING INTO the CAT is beyond
what the CAT can deal with, therefore the crap coming out of the CAT is
reasonably dirty, and any report of being dirty is understandable. The
sensors AFTER the CAT make an assumption about what should come out based on
that which went in. But, what went in was more than the CAT can clean, so
the reoprt that what comes out is dirty is actually a good report. Bottom
line here is that you should not need to replace the CAT or the sensors that
are mounted downstream. Your issue is entirely upstream from the CATs.

The Codes P0202 and P0203 are telling you that the fuel mixture is out of
spec, I assume TOO RICH, and can't be made any leaner through adjustments
that the computer is able to affect -- the computer can adjust the Injector
ON Time to affect a change to the air/fuel mixture, but due to reasons
elsewhere in the system, the computer can't do its job properly and the
P0202 & 203 reports are simply telling you this.

My guess is that your O2 Sensors, all 4 of them, are actually working right,
and something in the Fuel Delivery System is running amok causing a TOO RICH
condition that the sensors are properly reporting.

Conversely, you could have a vacuum leak that is causing a TOO LEAN
condition, but I would not expect TOO LEAN to be something the After CAT O2
Sensors would care about -- if the mixture was lean, then it would lack fuel
and therefore it would be clean by definition, and the CAT should be
reported as working well; which is cause to not report a Code.

I think you have a TOO RICH condition that is properly reported by the Codes
P0202 and P0203, and the resulting exhaust stream that exits the CAT is also
TOO RICH and the P0233 and P0234 codes are also accurate.

Having said all of that, review the link I gave you because the codes you
supplied should iron out to INJECTOR MALFUNCTION on #2 and #3 cylilnders,
and the P0233 and P0234 codes indicate some kind of Fuel Pump problem and an
Overboost Condition from the turbo charger, respectively.

"John Carrier" > wrote in message
. ..
>
> "RJD" > wrote in message
> news
>> On Thu, 07 Feb 2008 10:10:54 -0500, Jinks >
>> wrote:
>>
>>> I have a 1997 328iC that is throwing catalytic converter codes along
>>>with O2 sensor codes. Both me & the local converter expert suspect the
>>>problem
>>>is actually more the O2 sensors than the converters, so I'm going to try
>>>replacing them first. The problem is that BMW wants $200 + each for 4 of
>>>'em!
>>>That makes the sensors worth over $800!
>>> Does anyone know where I can find some after market O2 sensors at a
>>>reasonable price?
>>>-
>>>
>>>Jinks ('86FXRS, '07 FLTR)
>>>#64
>>>Remember, "No good deed goes unpunished"
>>
>> You can get replacement sensors from just about any well stocked parts
>> store. You can get them without the BMW dedicated connector for
>> approximately $50-70 or with the connector for around $100.00 a piece.
>> If yours have never been replaced it is a past due maintenance item.
>> The general consensus is about 100K miles before replacement but they
>> do deteriorate with time. They can be tough to remove but a little
>> heating from a torch works wonders.
>
> You can also approach the replacement as a phased effort. The sensors
> upstream of the converter are the more important and when they fail, your
> ECU will tend to overrichen the fuel mixture and impact mileage. Replace
> them first, reset the OBD and see if that solves all or most of your
> problems. If not, then pursue the rear pair.
>
> R / John
>

I agree with John, but the OP says that both upstream sensors are bad, and
this sets off the alarms in my head. It is possible for both sensors to fail
at the same time, but I'd be thinking that there is something that is common
to them from the perspective of the rest of the system that is setting them
off.

My theory on this one is that the sensors are properly reporting a condition
that is out of spec, and that there is a repair needed other than replacing
the sensors. Having said that, a '97 should need new stuff about now ...