O2 Sensor code because of not having sensor in X-pipe?

[Fidhle007]

So I fired up my S50 at 3 AM this morning finally but it throws an O2 Sensor code after about 5 minutes. I'm running on open headers for the moment with the sensor in the bung on the rear bank. Is it because it's only in half the exhaust stream that it's throwing the code or is my sensor fried?

[matt]

It's the sensor. It doesnt know that its only seeing half the flow.

[Fidhle007]

Alright, it's an old sensor out of the M3 anyway, I figured it might be shot. I'll throw the one from my E30 in there until worldpac can get me a new one.

[golde30]

the e30 one is fine no? thats what im using... is there any difference?

[KangamangusDriver]

MAF working properly?

Could be seeing incorrect air/fuel ratios.

Stock injectors?

Is it at operating temp?

Glad to hear it is running!!

[hoveringuy]

No difference. All the 4 wire Bosch sensors are the same unless they are the new "quick light off" variety. They change the plug for different cars.

I replaced mine just to see if it would get rid of the O2 heater issue but it didn't. I still get it intermittently, especially when the car is warming up.

Mine only sees 1/2 the stream as well (before the x pipe)

[matt]

Oh, BTW it may not be the sensor. It will sometimes throw the O2 code for vacuum leaks in the intake, so check that too.

[Fidhle007]

Actually, now that I think about it, there is a little rubber tube coming off the rear of the intake mani (I assumed it was a drain) and another hose fitting coming off the throttle body. And now that I just said that I realize that that's the vent for the charcoal canister so maybe I should just cap that and see if that fixes the issue...

[scabzzzz]

Dont cap that. Put it into a charcoal cannister. Just use the E30 one.

[Fidhle007]

Which doesn't fit...

[Fidhle007]

Swapped in another sensor that was fine in my M20 but I'm still getting the code. I guess I have to assume a vacuum leak at this point or could it be something with my wiring harness?

[gazellebeigem3]

Dont cap that. Put it into a charcoal cannister. Just use the E30 one.

truth.

[Fidhle007]

Ok, I'll do that tomorrow, but could not having that diverter valve be throwing that code somehow? I plugged up the little hose coming off the rear of the intake mani that didn't seem to run to anywhere but definitely would have been a vacuum leak.

[FLUTE007]

how does the code read? (word for word)

[Fidhle007]

13 02 Sensor Circuit