The distributors give a BUNCH of problms on this engine!!! Probably isn't missing that you can tell. No real good test for it either, other than replacement. Sorry. That is my GUESS, others may follow but they will be the same, a GUESS! I don't know for sure on your vehicle but if a crankshaft position relearn can be performed, it just might work! Nissan tech. would/may know.
It works on some, most of the time the check engine light is flashing without an actual misfire, this will fix it,, on 'some' that is. Just haven't run into this one, YET. Keep that distributor in mind!