[coriolis14]

Hi everyone -

First off, I'm kind of a noob when it comes to doing auto maintenance but this forum has been an incredible resource and has taught me how to do a lot with my car! I'd like to thank you all for your help!

Now to the problem:

I've been getting a consistent O2 sensor error for the past 4 months (error code 2C32) that is starting to get very annoying since I have to clear the SES light every month or so (currently using BMW Logger). I've taken the car into my indy shop a few times, but they claim the O2 sensor is working normally and just clear the code as I've done over the months.

My Car:
2007 E92 328i
N51 - 6AT
Odo - 68,000

I'm driving my car bone stock with no mods since it was new. I've done some research on the issue, but I haven't found anything relevant to the N51/N52 engine. Most of the other cases I've found were due to exhaust mods on N54s.

I have, however, had to replace my catalytic converters under warranty since my car failed a CA smog check last year. I'm not sure if this has to do with anything since the error (2C32) is for the O2 sensor before catalytic converter 2. I honestly have no idea what is going on at this point and neither does my indy (or so it seems).

I was hoping someone with a similar experience might have some insight on what is going on! Any advice would be welcome!

[jeguth1s]

I assume you tried a new O2 sensor?

[coriolis14]

My indy shop replaced it once already 2 months ago. I may have them try a new one again next week if I can't find another solution.

[TheSt|G]

Originally Posted by coriolis14

My indy shop replaced it once already 2 months ago. I may have them try a new one again next week if I can't find another solution.

Did they replace it with OE or OEM?

02 sensors are pretty delicate in general. Most people who have removed and replaced them(header installs, manifold swaps, CAT swaps) have had a failed sensor shortly after.

[coriolis14]

My indy says everything they use to make repairs is OEM and I have no reason to doubt them (I've looked their maintenance/repairs done prior to this one and they check out OK with BMW labels/part #s).

Sounds like I should just take it back and have them try a new one!

[TheSt|G]

Originally Posted by coriolis14

My indy says everything they use to make repairs is OEM and I have no reason to doubt them (I've looked their maintenance/repairs done prior to this one and they check out OK with BMW labels/part #s).

Sounds like I should just take it back and have them try a new one!

OE=BMW Parts
OEM=Parts made by the BMW supplier

[thomas88162]

It could be a vacuum leak. Does the code set more often while idling?

[MarkkyyMan]

Check for exhaust leak.

[Efthreeoh]

Your indy sounds a bit lame to me. Sorry but an answer of just keep clearing the light doesn't seem like a good answer. Any decent shop should use a scan tool to evaluate the performance of the O2 sensors and determine if they are functioning correctly. It could e the cats are defective again. A vacuum leak would show as a lean running condition. The car needs a complete scan under operation to check fuel trim, engine load, O2 operation, etc. Seems to me your car being in California and under 80,000 miles it is still under California emissions warranty. Maybe you should check in that and take it to a BMW dealer instead.

[coriolis14]

Originally Posted by TheSt|G

OE=BMW Parts
OEM=Parts made by the BMW supplier

My mistake! My indy only uses BMW Parts (OE Parts).

Originally Posted by Efthreeoh

Your indy sounds a bit lame to me. Sorry but an answer of just keep clearing the light doesn't seem like a good answer. Any decent shop should use a scan tool to evaluate the performance of the O2 sensors and determine if they are functioning correctly. It could e the cats are defective again. A vacuum leak would show as a lean running condition. The car needs a complete scan under operation to check fuel trim, engine load, O2 operation, etc. Seems to me your car being in California and under 80,000 miles it is still under California emissions warranty. Maybe you should check in that and take it to a BMW dealer instead.

My indy has performed a vacuum test each time I've brought the car in and each time it's come up with no results (there are no leaks in the system, per their tests). After the vacuum tests, they would then clear the code.

As for the catalytic converter going bad again - I originally thought this might be the issue, but the code (2C32) specifically refers to the O2 sensor before the cat. I'm not sure a bad cat would trip this sensor since it is located earlier up the exhaust stream. I'll have my indy look into whether the cat has gone bad again as well.

To be honest, I have been a bit troubled by this whole oxygen sensor issue with my indy...but they've always been honest with me in the past and seem competent. They haven't given me a reason to be suspicious or doubt their abilities. I've made an appointment with them for next week and will get back to you all with the answer they give me!

Thank you all for your input! I appreciate it!

[thomas88162]

How does the area around your valve cover look? It IS a bit of a stretch, but a lot of oil seeping out around the gasket could contaminate the 02 sensor wiring looms, shielding or not.

[coriolis14]

Originally Posted by thomas88162

How does the area around your valve cover look? It IS a bit of a stretch, but a lot of oil seeping out around the gasket could contaminate the 02 sensor wiring looms, shielding or not.

I checked around the valve cover, but there's no trace of oil (thank God).

I am getting a new error now though in addition to my original 2C32: 2C6C (O2 sensor after cat 2). I'm beginning to think there might be something wrong with the cat that BMW installed...

I'm not sure if I should keep driving my car (I use it as my DD ~50 miles round trip to and from work in mostly city driving). Anyone with a good reason think I should park it and borrow my sister's car until I get this looked at?

[thomas88162]

If BMW installed it, there is a 2 year warranty on it. They will honor any repair IF it's the cat. It sure does sound like it could be, but then it is possible that something else caused it to fail again, like rich running, or a constant misfire for that matter.

[bmwfastlife]

Originally Posted by coriolis14

My mistake! My indy only uses BMW Parts (OE Parts).



My indy has performed a vacuum test each time I've brought the car in and each time it's come up with no results (there are no leaks in the system, per their tests). After the vacuum tests, they would then clear the code.

As for the catalytic converter going bad again - I originally thought this might be the issue, but the code (2C32) specifically refers to the O2 sensor before the cat. I'm not sure a bad cat would trip this sensor since it is located earlier up the exhaust stream. I'll have my indy look into whether the cat has gone bad again as well.

To be honest, I have been a bit troubled by this whole oxygen sensor issue with my indy...but they've always been honest with me in the past and seem competent. They haven't given me a reason to be suspicious or doubt their abilities. I've made an appointment with them for next week and will get back to you all with the answer they give me!

Thank you all for your input! I appreciate it!

I know this is reviving an old thread but did you ever get a resolution for your problem? I am having the same problem with my 2008 328i. Thanks

[Eagle1oh7]

Have you tried MAF sensor? I had some lean codes pop up when my AFE box MAF gasket deteriorated causing air to be sucked in where the MAF is installed. Try spraying it down with MAF cleaner. It might be worth a shit.

[PhaseP]

Originally Posted by bmwfastlife

I know this is reviving an old thread but did you ever get a resolution for your problem? I am having the same problem with my 2008 328i. Thanks

Well usually listen to the patient, especially when it has lots of CPU power
If the car is saying oxygen sensor, change the oxygen sensor.

[Illoosive]

Originally Posted by bmwfastlife

I know this is reviving an old thread but did you ever get a resolution for your problem? I am having the same problem with my 2008 328i. Thanks

This has been happening to me for the past months. I've replaced every sensor it has said to replace. Codes just 1 keeps coming back 2C32.