O2 sensor for E28

[kmitch@xxxxxxxxxx (Howard K Mitchell)]

First of all, thanks to the 4 people who responded to my post looking for
the alternative O2 sensor for the 535i.  I now have an O2 sensor in, but
the car is now running very rough and sluggish.  I bought the item you guys
suggested, with three wires (Bosch part #13942, for Ford 5 liter, 1990-93),
buy my mechanic and I ended up installing a single-wire Bosch unit instead,
because there was only one black wire coming out from the wiring harness.
I don't have the old wiring or connector from the old sensor (which might
have helped us figure this situation out), so we just crimped on a
connector and spliced the black wire into the black lead that came out of
the wiring harness.  There WAS another wire there, a green one I think, but
we didn't know what to do with it.  My mechanic thought that it may have
been for sensors with a heating component to get the sensor up to temp and
working quicker?

In any case, with this unit installed, I now have a very rough-running car.
Does anyone have any ideas?  Should I go with the other part (#13942)?  If
so, do the white wires (or one of them) connect to the green one in the
harness?  Should I just go back with the original part for my model (which
is priced about $80 more than the Ford application part)?

Any help with this situation would be greatly appreciated.

Ken Mitchell
'87 535is

------------------------------