Okay, my father in law and husband are changing the O2's next week. Now, how do I figure out which ones to buy? On the write up that Ford gave me, it just says:

Upstream O2
R&R both lack switch

When I look at Schucks.com it doesn't say anything about "upstream", just rear, left exhaust etc.

Jen, bank 1 is the passenger side, bank 2 is driver's side. The upstream sensors referrs to the ones closest to the exhaust manifold; downstream are the ones after the catalytic converters.

Therefore the ones you want are the "front" (upstream) left and right (bank 1 & 2).

At the parts store they are all the same! An o2 sensor is an o2 sensor nothing changes front or back.

they'll need to know if you need long wire or short wire. That's what they asked me anyway for my 96. I don't know the answer though.