Replaced all of mine a couple of months ago as they were original and all giving errors. The oem is bosch so that's what I ordered. when I pulled mine out they atually said motorcraft bosch. I ordered mine from rockauto. I believe they listed a left and right upstream because one of the pigtails is longer than the other along with the downstream. I ordered all three and they fit perfectly. Haven't had any issues or errors since.

 

It's because the catalogs Ford dealers use (myself included) are archaic for anything made before 2005. Ford lists them sort of oddly anyway though. According to FoMoCo, your upstream should be DY1401 (even though it uses the 9G444 base of a downsteam O2), and your downstream should be DY1094 (which is obsolete, however plenty of dealers still show them in stock).

 

i'm 99% sure the differences between upstream and downstream is just the length of the pigtail. so you could potentially get the one with the longer pigtail (can't help you on which one is which) and use it in the short position.

also, aftermarket is fine here.


*edit according to rock auto, the downstream has the longer pigtail. they have both upstream and downstream available through bosch and delphi, among others.

 

Thank you all for your replies. Much appreciated.

 

sensors essentially are the same for up and downstream. what can differ is the pigtail length, connector color and sometimes an indexing nub on the connector. but when it comes to replacements, most new sensors will fit regardless. some places will even list 'alternative fit' part numbers which will have longer pigtails

Motorcraft basicly just uses Bosch so you might have an easier time just getting Bosch.
Bosch 15716 for upstream and 15619 for down. the upstreams have a 10" pigtail vs the down having a 24"

i would recommend Rockauto as its cheaper and you wont get sold counterfeited parts

 

Thanks.