02 sensor

[gofast at ix.netcom.com]

Hi. Doing a service on my BMW 635, and want to replace my 02 sensor. The BMW 
O2 sensor cost $140; Ford use Bosch O2 sensors on the Mustang 5.0 for $60, 
which is also what aftermarket 3-wire sensors from NAPA cost.

Are there any differences between O2 sensors? Is there any reason to use the 
stock one? Is the ECM calibrated to use the output from a specific unit?

>From the archives, I kind of understand that most of these give similar 
results at stochiometric (0.45v), but I'm concerned about the cars ability to 
correct the mixture if its given incorrect inputs.

Thanks in advance.

Samir Shah
gofast at ix.netcom.com
Stamford, CT