"FoggyBottom" > wrote in message
...
> It occured to me recently that my 13-year old 148000-mile 325iX is
> running with its original O2 sensor. No complaints from the ECU and
> out of sight, out of mind applies. I see that the recommended
> replacement interval for this thing is 60K. Oops. That said, if it's
> working, is it really necessary to replace it? If so, is that special
> tool BMW recommends (it looks like a cross between a crow's-foot
> socket and a shark's mouth) really necessary? With it seeming to be
> working correctly this strikes me as letting a sleeping dog lie. Or
> am I giving up power/performance/mileage that's not immediately
> apparent? No problem with emissions testing, BTW.
>
> If "replace it" is the answer, who do you like for the replacement
> part? What's a good price?

If it's running well and you're passing emissions, I'd leave it. It's a
torch job to get it out at this point, no question.

I replaced mine with a Ford Mustang 4-wire sensor and cut the harness off
the spent BMW sensor. Was a lot cheaper than the BMW part.

-Russ.