When I bought my r33s2 it had 30,000 ks up and was roughly 10ks to the litre at about the 40,000k mark that dropped to 7.5 ks to the litre and lots a black soot all over ass end, alot happened around that time (upgrades and a fly through air thump on ground thingy) but subsequent investigations by mechs said the car/fuel use was OK!
After reading all this thread i decided to try it out.
I just bought O2 sensor from autobahn Part #OX207 for falcon EL $80.00 my wiring was
Nissan ------>Ford
Black ------->Black
Black ------->Black
White ------>Blue
Crimped wires together shielded them seems to run OK
Will let you know if any improvement.