my pathfinder will start sometimes but other times when cranking over it won't

What is your question?

Ok I can start my Pathfinder sometimes and sometimes not. It will try to crank over but it wont start it shutters after I stop trying to turn key. It almost started today after I stop trying to turn it over it seemed like it was going to start on its own all of sudden. what is that? why is it doing that? I have put gas treatments in the gas which gets it to start every time. I am going to put new fuel filter on today. I thought it might be bad gas but I was having issues on freeway two days ago it was puttering sputtering a little back fire noises not big when I gave it gas it would back fire a little and I put it in overdrive to see if it would help it resolved the issue it drove like an angle after that. Is it gas issues? Any ideas?

What makes this problem better or worse?

gas treatment makes it better

How long has your 1995 Nissan Pathfinder had this problem?

a month or two