Just to give you a better idea, Bank 1 refers to cylinders 1-3-5 and are located near the firewall while Bank 2 are for cylinders 2-4-6 and are closer to the radiator. Front O2 sensor (before 'cat') has a 3-wire connector while rear sensor (after 'cat') has 4-wire connector. The O2 sensor can get damaged if mishandled- DO NOT DROP IT.
The sensor you need is the Front Right O2 sensor (Item #1) shown in the link from IoS (Infiniti of Scottsdale):
http://www.infinitipartsusa.co...gid=0
Ios is the best place to buy OEM parts but when it comes to spark plugs and O2 sensors, "sparkplugs.com" a.k.a. "NGK.com" is preferred. The front (left or right) sensors are identical (NGK 24525) but the rear sensor part numbers are different, depending on the production date - before or after 07/96. See the link below
http://www.ngk.com/results_app.asp
That NGK 24525 O2 sensor is available right now at a cheaper price ($57.28) from Amazon with free shipping too. You may get an NTK instead of an NGK but they are essentially from the same manufacturer. You might as well buy an O2 sensor adapter.
http://www.amazon.com/s/ref=nb...0&y=0