the codes for the bank are numerical, i don't know if that explains it correctly or not, but for example if Bank #1, Upstream is say 124, than Bank #2 Upstream should be 125.......I could be wrong tho. I just went thru the same thing. Save some money if its not under warranty, go to Your local advance and pick the downstream one up for 65 and upstream is 75ish I think. Downstream P/N is 13133 Bosch.
