I replaced all 4 of mine. Had poor results with the $50 Bosch splice in sensors. Ended up having to go for the $100 plug and play Bosch units due to fighting o2 codes for a few months. Resetting adaptations was key though after replacing all 4. Just my experience though.

Mu precatalyst sensors were just under $65 from FCP Euro. Not sure if the V8 uses a different sensor thank the 3.0 :dunno:

https://www.fcpeuro.com/products/bmw...or-bosch-13477

Yep, they do. V8 guys get taxed again. :( Sorry, for some reason I thought they would be similarly priced. At any rate, I agree @ 180k, they're due for replacement.

This happened to me On my 4.4 2005. I replaced all O2 sensors as they were reading slow. And the monitor never set. Replace them then do an adaptation reset and drive it.


Side note: I never had a check engine light on.


Edit: I purchased the OE sensors at Rock auto, they were the cheapest one about $100 total in difference.