O2 sensor dead....already?

[BMWManiac]

My idle AFR has jumped up to around 18-19....I got the CEL while driving and the codes, once again, read CA/E3 which point to the O2 sensor. I replaced it just a couple months ago when I had these codes and all was well...I'm wondering if the sensor dying has been the reason behind my car running rich on low boost and now finally it is just about dead. I'd hate to replace it every couple of months!

[BMWManiac]

and the issues keep coming....vacuum at idle around 16 and AFRs up there in the 18/19s.....I have an O2 sensor enroute, but now I need to look for that damn vac leak. I bet its a pin sized hole somewhere that will be a nightmare to find....

[NickG]

Which way is your O2 sensor mounted/positioned? Is the pigtail below the sensor's tip? If so, condensation can run down into the sensor and cause it to have a very short life. The pigtail/wiring needs to be 'above' the level of the tip, so condensation doesn't run down into it.

[BMWManiac]

i'll check, but I believe the pigtail runs down towards the sensor and sits above or even with the sensor itself. If not, I guess I can pull it a little bit more taut so that it is above the sensor

[NickG]

No, you're not understanding me. When I say condensation runs down into the sensor, I mean from INSIDE the exhaust system, from the sensing tip.

The pigtail end of the sensor needs to be pointed between 10 o'clock -> 2 o'clock (upwards), so water that's inside the exhaust can't run down into the sensor's body.

[BMWManiac]

Ah, gotcha....last time I replaced the sensor, it was pretty much perpendicular into the downpipe...