Days ago I just posted what of the 4 O2 sensors in my '00 I30t is the BANK 2 Sensor 2, so I just called GRUBBS INFINITI in Dallas and the guy at the parts counter just talked with the Service Technician and solved my problem, the BANK 2 SENSOR 2 is the one with the RED WIRE, so any one that need this info can use it, just to let you all know ! Hope this help some one !!!