ok my buddy and i installed a safc2. wired everything up as it was so to, cleared memory and all. Got all the sensor to check out, the knk sensor as well.. the only issue were having now is the rpm display on the safc2 is reading backwards.
(ex) at idle 6900rpms-7400rpms
WOT = 1500rpms -1000rpms

did anyone else have this problem?
we figured out but just messing around ( if we had the cylinder number set on 16 we were able to get the numbers to read 2800rpms at idle and go up to 8400rpms at WOT but i dunno what else to do here?)

this is on a 2004 maxima 6spd

 

Make sure you're using the right car type (6cyl) and you used the correct wire for the RPM signal.