EmanMax97

So I have automatic 97 maxima 218kmiles with a stalling problem. Happens randomly, used to misfire but changed all ignition coils and that helped as well as one fuel Injector that wasn't working right. Changed the idle air control thing also. There's only one code which is the knock sensor and I'm getting tired of putting new things into it. Anyone else have had this problem. Is there a way to diagnose it with the engine running so it can maybe see what's wrong?