Fault Code PO 141(1/2 O2 sensor relay)
 

HELP
My 2001 X-5 3.0 with 106.000mi. run fine but the ckeck engine light comes on and off frequently. I can't get it thru inspection till corrected, put my scan gauge on and got the PO 141 code (1/2 oxygen sensor relay reading.) I don't know where the relay is located so I can replace it also can it be the sensor itself? Any help appreciated.

PO 141 for me meant a faulty o2 sensor post-cat converter (something about a preheater). You need a replacement sensor and can get at the sensor from underneath the car.

Was you auto an X-5, my code said 1/2 relay bank using a scangauge2. Do you ynow where the relay is and how to test?

Stick shift; I used an actron scan device. No idea on the relay

which one of the post cat converter o2 sensors did you replace? thanks.

Got it finally corrected after I replaced all four O2 sensors. The bad sensor was the rear (underneath-post) sensor, BMW suggests you replace all four at 100,000mi, good to go for another 100k. Thanks!