oxygen sensor

Can anyone tell me which sensor is the downstream oxygen sensor on a 1998 dodge intrepid?

You have two if I am not mistaken. There will be one on each side After the cats.

I'm told there are three, but i'm interested in only changing the downstream not upstream sensor but I don't know which is which on either the driver side or passengers side?

You have two downstream sensors, one is on the drivers side and one is on the passenger side. The downsteam sensors are closer to the back of your car.

thanks