[illini313]

My car:
E90, 2006 325i, Built 06/2005

My problem:
Service Engine Soon light illuminated

Troubleshooting:
Diagnostics read found the following codes:
- P0597: Thermostat heater control circuit open
- P3027: ? (O2 sensor operating temp. not reached (B2S1))?
- P2247: O2 sensor circuit open (Bank 2 Sensor 1)
- P0050: Heated O2 sensor (Bank 2 Sensor 1) / Heater control circuit
- P0155: Heated O2 sensor (Bank 2 Sensor 1) / Sensor heater circuit

Assumption:
Oxygen sensor needs to be replaced
- Bank 2 Sensor 1 (precat)
- rear manifold cyl4-6????

My Question:
Is the B2S1 O2 sensor easily accessible under the hood?

I only have wrenches, sockets, and basic tools. I do not have adequate tooling to safely work underneath the car. I would prefer to repair this myself instead of going to a mechanic. I have not been able to find any DIY guides for this specific sensor on this specific model.

I may have located the sensor, but I'm not sure if it's the correct one. Please see the attached photos. (Sorry for the poor quality - they were taken with a BlackBerry in dim lighting).

I'd appreciate any advice.

Thanks!

BM

[ENINTY]

Based on what you said were your tools you have available to you and not a lot of wrenching experience (my assumption), take the car to an independent BMW mechanic and have them replace the O2 sensors. O2 sensors are a royal pain in the ass to remove because they get frozen in place in the exhaust. The tremendous heating and cooling cycles plus the exhaust gas particulates really lock the threads up. At a minimum you'll need a special O2 sensor removal socket, a strong 1/2 breaker bar, extensions, lots of penetrating oil, and usually a piece of pipe to extend the torque you apply to the breaker bar. Also, the space you will be working in is very tight and doesn't allow use of normal tools. A good mechanic will have the proper special tools to remove the sensors safely and quickly; it will be well worth your time to pay him to do it.

[F32Fleet]

Originally Posted by ENINTY

Based on what you said were your tools you have available to you and not a lot of wrenching experience (my assumption), take the car to an independent BMW mechanic and have them replace the O2 sensors. O2 sensors are a royal pain in the ass to remove because they get frozen in place in the exhaust. The tremendous heating and cooling cycles plus the exhaust gas particulates really lock the threads up. At a minimum you'll need a special O2 sensor removal socket, a strong 1/2 breaker bar, extensions, lots of penetrating oil, and usually a piece of pipe to extend the torque you apply to the breaker bar. Also, the space you will be working in is very tight and doesn't allow use of normal tools. A good mechanic will have the proper special tools to remove the sensors safely and quickly; it will be well worth your time to pay him to do it.

+1

www.bimrs.org

[graham1228]

I have a BMW 325xi built 06/2006 w/ 107,000 miles and I am going to replace both pre-cat O2 sensor's.

Currently throwing these OBDII codes:
P3027 = O2 Sensor Operating Temperature Not Reached (Bank 2 Sensor 1)
P2247 = O2 Sensor Reference Voltage Circuit/Open (Bank 2 Sensor1)

Does anybody have a good DIY writeup and/or have the correct Bosch part number's?

I have found these part number's so far:
Bosch
11787558055
11787558073

Additional Car info:
Series E90
Model 325xi
Body type saloon
Catalog model USA
Production date 2006 / 06
Engine N52
Transmission Manual
Steering Left
Catalyzer YES

[ENINTY]

Originally Posted by graham1228

I have a BMW 325xi built 06/2006 w/ 107,000 miles and I am going to replace both pre-cat O2 sensor's.

Currently throwing these OBDII codes:
P3027 = O2 Sensor Operating Temperature Not Reached (Bank 2 Sensor 1)
P2247 = O2 Sensor Reference Voltage Circuit/Open (Bank 2 Sensor1)

Does anybody have a good DIY writeup and/or have the correct Bosch part number's?

I have found these part number's so far:
Bosch
11787558055
11787558073

Additional Car info:
Series E90
Model 325xi
Body type saloon
Catalog model USA
Production date 2006 / 06
Engine N52
Transmission Manual
Steering Left
Catalyzer YES

I did a DIY on the Bank 2 Sensor 1 Ox sensor in December 2010. It's in the DIY section. The Bank 1 Sensor 1 Ox sensor is easy because it is accessible from up top. The Bank 2 Sensor 1 (cylinders 4, 5, and 6) is much harder because it is not easily accessible from the top and you need to get under the car to remove it. I have a car lift so it was easy to get to. If you have the car on jack stands it will be much harder because if you are lying on your back it would be a PIA. Also the technique I used may not work for an Xi car because the front drivetrain may be in the way.

The good news is the sensors unscrew from the exhaust manifolds pretty easily; they are not frozen in the manifold like most other cars I have worked on. If you haven't yet replaced the spark plugs do them at the same time because you need to remove all the parts on top of the engine to remove the sensors, so while you're in there do the plugs too. My advice is get a good Ox sensor removal tool. I got my sensor from Tischer (getBMWparts.com); their price was quite reasonable and it was OEM.

I've included my word version of the DIY so you can print it out and use as a reference.

[graham1228]

That was exactly what I was looking for, thanks ENINTY.

Also, I do not own a BT (BMW) scan tool, do you think AZ or OReilly's can clear the SES trouble Code with their OBD II scan tool?

[ENINTY]

Originally Posted by graham1228

That was exactly what I was looking for, thanks ENINTY.

Also, I do not own a BT (BMW) scan tool, do you think AZ or OReilly's can clear the SES trouble Code with their OBD II scan tool?

I've never used an autoparts store to read a code. I've heard that they don't clear codes for liability reasons. Autozone just gives you the tool to borrow (after you leave a deposit, or you license) and you can clear the code yourself.

The procedure calls for clearing the code BEFORE you remove and replace the sensor (and re-energize the ignition), so if you can get the code cleared and drive home before the system does a self check (and throw the code again) then you should be okay. Sears sells a nice OBDII scan tool for $49.99. A scan tool, even a simple one, is a good tool to have just to understand what codes are present.

[nyc4runnin]

Originally Posted by graham1228

I have a BMW 325xi built 06/2006 w/ 107,000 miles and I am going to replace both pre-cat O2 sensor's.

Currently throwing these OBDII codes:
P3027 = O2 Sensor Operating Temperature Not Reached (Bank 2 Sensor 1)
P2247 = O2 Sensor Reference Voltage Circuit/Open (Bank 2 Sensor1)

Does anybody have a good DIY writeup and/or have the correct Bosch part number's?

I have found these part number's so far:
Bosch
11787558055
11787558073

Additional Car info:
Series E90
Model 325xi
Body type saloon
Catalog model USA
Production date 2006 / 06
Engine N52
Transmission Manual
Steering Left
Catalyzer YES

unless the oem sensors are made by bosch, i would not get them again....
i got bosch sensors to replace denso's in my toyota and they were worthless, needed to get oem denso sensors for the codes to stay clear.

[psre08]

While we're on the topic, I've been waffling on replacing an O2 sensor for months (bank 2 post-cat).

Can someone confirm the 'banks'? I need to make sure I have it right. Realoem doesn't exactly help unless you know what you're looking at... the '3d' blown out display doesn't really work for me.

Bank 1 pre-cat = cyl 1,2,3 - the most visible O2 sensor towards the front of the engine
Bank 2 pre-cat = cyl 4,5,6 - the one towards the rear of the engine, still visible by just opening the hood and peering inside
Bank 1 post-cat = cyl 1,2,3 - under the engine (not sure where), never actually seen it.
Bank 2 post-cat = cyl 4,5,6 - last O2 sensor before the long mid-pipe running under the vehicle.

[ENINTY]

Originally Posted by psre08

While we're on the topic, I've been waffling on replacing an O2 sensor for months (bank 2 post-cat).

Can someone confirm the 'banks'? I need to make sure I have it right. Realoem doesn't exactly help unless you know what you're looking at... the '3d' blown out display doesn't really work for me.

Bank 1 pre-cat = cyl 1,2,3 - the most visible O2 sensor towards the front of the engine
Bank 2 pre-cat = cyl 4,5,6 - the one towards the rear of the engine, still visible by just opening the hood and peering inside
Bank 1 post-cat = cyl 1,2,3 - under the engine (not sure where), never actually seen it.
Bank 2 post-cat = cyl 4,5,6 - last O2 sensor before the long mid-pipe running under the vehicle.

This is correct.

[DJ Apex]

sorry to bring up a old thread but i need help lol im throwing a p2196 and a p2198 meaning bank 1&2 Sensor 1&1 stuck rich. i just recently deleted my factory cats on my header. i had my car retuned to accept catless headers. so my issue is maybe i should move my precat o2s down stream to were the after cat o2s are since they are off i have no use for them. im thinking its just reading off cause less back pressure or something i cleared my ses light im gonan wait till it pops up cause i now bank 2 sensor 1 will pop up. soon and i wanan see if its just bank 2 or did bank 1 pop up again. if bank 1 poped up then its not my 02 that is bad its another issue

[GRLPWR]

Bank 1 pre-cat = cyl 1,2,3 - the most visible O2 sensor towards the front of the engine
Bank 2 pre-cat = cyl 4,5,6 - the one towards the rear of the engine, still visible by just opening the hood and peering inside
Bank 1 post-cat = cyl 1,2,3 - under the engine (not sure where), never actually seen it.
Bank 2 post-cat = cyl 4,5,6 - last O2 sensor before the long mid-pipe running under the vehicle.

This is great to know, but would someone be so kind as to clarify which is Sensor 1/2 for each bank? Is pre-cat Sensor 1 and post-cat Sensor 2?

Bank 1 Sensor 1
Bank 1 Sensor 2

Bank 2 Sensor 1
Bank 2 Sensor 2

I'm throwing an O2 sensor swap code Bank 1 Sensor 1 / Bank 2 Sensor 2 and I'm trying to figure out which is where. I recently had both pre-cats swapped and replaced one of those. Don't understand why I'm getting this code now.

[ENINTY]

All catalyst cars have two O2 sensors per catalytic converter. Two are needed to determine the effectiveness of the catalytic converter. The O2 sensor positions are "up-stream" i.e. measure exhaust gasses ahead of the catalytic converter and "down-stream" i.e. measure exhaust gasses behind the catalytic converter. In OBD II nomenclature, all up-stream O2 sensors are referred to as "Sensor 1"; all down-stream O2 sensors are referred to as "Sensor 2".

[GRLPWR]

Originally Posted by ENINTY

All catalyst cars have two O2 sensors per catalytic converter. Two are needed to determine the effectiveness of the catalytic converter. The O2 sensor positions are "up-stream" i.e. measure exhaust gasses ahead of the catalytic converter and "down-stream" i.e. measure exhaust gasses behind the catalytic converter. In OBD II nomenclature, all up-stream O2 sensors are referred to as "Sensor 1"; all down-stream O2 sensors are referred to as "Sensor 2".

Ahhhh, If that's the case, I'm surely confused now with the code I'm throwing. How can I have a pre- and post-cat sensor swapped code? (O2 sensor swap code Bank 1 Sensor 1 / Bank 2 Sensor 2)

Question regarding post-cat sensors - is it true those are different (brand/price) than the Bosch pre-cat sensors used? I had a tech at a stealership tell me they don't use the same brands. The post-cat sensors are about double the price and of a different brand (don't remember brand) than what's used for pre-cats.

[halcyon026]

I noticed when looking for o2 sensors from the online parts stores they list them as Front/Rear Oxygen Sensor - Left/Right OR Front/Rear Oxygen Sensor - Upper/Lower.
http://ebmwparts.com/parts/2008/BMW/...agramCallOut=4
http://www.ecstuning.com/BMW-E90-335...ine/Emissions/

I added an image showing the part numbers. If anyone can help me with the correlation between Front/Back;Upper/Lower & Bank X/Sensor X, I can update the image & we'll know how to interpret the sensor location for Error codes like;
"P22AA: Nox Sensor Heater Sense Circuit Intermittent (B1S2)"

For ordering parts we need to know, is "Bank X" referring to Front/Back, Left/Right or Upper/Lower? Then if it's referring to Front/Back, which one is "Bank 1"? Same goes for "Sensor X", is it referring to Left/Right, Front/Back or Upper/Lower & which one is "Sensor 1"? Then we'd need to know the correlation between Left/Right & Upper/Lower.

Here's what I think I know based on other threads.

Bank 1, Sensor 1 = cyl 1,2,3 - the most visible O2 sensor towards the front of the engine
Bank 2, Sensor 1 = cyl 4,5,6 - the one towards the rear of the engine, still visible by just opening the hood and peering inside
Bank 1, Sensor 2 = cyl 1,2,3 - under the engine (not sure where), never actually seen it.
Bank 2, Sensor 2 = cyl 4,5,6 - last O2 sensor before the long mid-pipe running under the vehicle.

My hunch is that Bank X is referring to Front/Rear & Sensor X is referring to Upper/Lower. Is that right?
If so, I'm guessing

Front, Upper = Bank 1, Sensor 1 (Number 6) (pre-cat) (PN: 11787558055)
Front, Lower = Bank 1, Sensor 2 (Number 7) (post-cat) (PN: 11787545074)
Rear, Upper = Bank 2, Sensor 1 (Number 8) (pre-cat) (PN: 11787558087)
Rear, Lower = Bank 2, Sensor 2 (Number 9) (post-cat) (PN: 11787545075)

Front = Bank 1
Rear = Bank 2
Upper = Sensor 1 (pre-cat)
Lower = Sensor 2 (post-cat)

Can anyone clarify this for sure? The 2nd image, I believe, is from another BMW fiche, not for the 335, but same idea.

[Efthreeoh]

Originally Posted by halcyon026

I noticed when looking for o2 sensors from the online parts stores they list them as Front/Rear Oxygen Sensor - Left/Right OR Front/Rear Oxygen Sensor - Upper/Lower.
http://ebmwparts.com/parts/2008/BMW/...agramCallOut=4
http://www.ecstuning.com/BMW-E90-335...ine/Emissions/

I added an image showing the part numbers. If anyone can help me with the correlation between Front/Back;Upper/Lower & Bank X/Sensor X, I can update the image & we'll know how to interpret the sensor location for Error codes like;
"P22AA: Nox Sensor Heater Sense Circuit Intermittent (B1S2)"

For ordering parts we need to know, is "Bank X" referring to Front/Back, Left/Right or Upper/Lower? Then if it's referring to Front/Back, which one is "Bank 1"? Same goes for "Sensor X", is it referring to Left/Right, Front/Back or Upper/Lower & which one is "Sensor 1"? Then we'd need to know the correlation between Left/Right & Upper/Lower.

Here's what I think I know based on other threads.

Bank 1, Sensor 1 = cyl 1,2,3 - the most visible O2 sensor towards the front of the engine
Bank 2, Sensor 1 = cyl 4,5,6 - the one towards the rear of the engine, still visible by just opening the hood and peering inside
Bank 1, Sensor 2 = cyl 1,2,3 - under the engine (not sure where), never actually seen it.
Bank 2, Sensor 2 = cyl 4,5,6 - last O2 sensor before the long mid-pipe running under the vehicle.

My hunch is that Bank X is referring to Front/Rear & Sensor X is referring to Upper/Lower. Is that right?
If so, I'm guessing

Front, Upper = Bank 1, Sensor 1 (Number 6) (pre-cat) (PN: 11787558055)
Front, Lower = Bank 1, Sensor 2 (Number 7) (post-cat) (PN: 11787545074)
Rear, Upper = Bank 2, Sensor 1 (Number 8) (pre-cat) (PN: 11787558087)
Rear, Lower = Bank 2, Sensor 2 (Number 9) (post-cat) (PN: 11787545075)

Front = Bank 1
Rear = Bank 2
Upper = Sensor 1 (pre-cat)
Lower = Sensor 2 (post-cat)

Can anyone clarify this for sure? The 2nd image, I believe, is from another BMW fiche, not for the 335, but same idea.

The second image is correct.

[Mus]

Hi,
Can someone help me with the following pleas; I have a 2006 BMW 3 Series with a N52 petrol Engine. The problem is that I have a check symbol on my dash and when I took my car for a checkup, the error code read faulty Oxygen sensor.

My question is how many Oxygen sensors dose a 2006 BMW with a N52 petrol Engine have?

And what type of sensor socket dose each have?

[Mrsn52e90]

^^ There are 4 O2 sensors on the N52.

[Saintor]

Mine is installed this way. There is a fixed bracket over and the wiring is attached down the way so I can't see how they can reach that clip.



I bought a O2 socket and an articulated wrench; that damn thing is still there. It is like it was never thought out that somebody would need to replace it without raising the engine. I can't believe that I will have to go to a BMW dealer for this.

I have 2C2D or 2C2E if I remember correctly.

[littlejohno]

OLD THREAD BUT WORTH A TRY
Just out of curiosity did any of you take readings from the sensors !!!! I'm trying to find data in order to check mine as they appear to be reading high POSSIBLY

[Michael BD]

can the o2 sensor simp-ly be cleaned instead of replaced?

[Efthreeoh]

Originally Posted by bornadog335i

can the o2 sensor simp-ly be cleaned instead of replaced?

No.