Test or replace 02 sensor? Correct replacement part no?

[r-mm]

My car has an o2 sensor of unknown provenance installed. The po who is older and now hard to get in touch with gave me a store brand replacement o2 sensor in a bag of parts im only now going thru. The car performs well but gets lowish mpgs. I just want to go thru it and ge it up to snuff. Im curious to know if the o2 sensor is working but bentely describes the test procedure as requiring a dme pinout tool. Is there any other way? Foolish to get the car up to temp with o2 connector removed then monitor voltage from the signal wire and a body ground?

Ill likey replace it even if its good, just from age. Is pelican part 15735-M14
The correct replacement for a 87 3.2 ?

Thanks pelicans

[Bob Kontak]

The Pelican part you reference is a three wire universal Bosch. I will work fine but you have to do some connecting yourself.

It is probably close to the same unit the PO gave you.

Is there a name brand and part number on the one the PO gave you? If so, it should be able to be cross referenced to a data base of application.

[r-mm]

Making the generic electrical connections are no problem - but the threads and exterior dims are exactly as they are supposed to be, right?