I've been having the same issue of it sputtering and threw a p0171 code i believe and then today it actually died after turning on. Wouldn't stay running without some throttle applied. I took the idle control out and tried turning the key to on to see what happened and it popped the whole plunger thing out, is that normal? The plunger screws back in and i can't pull it out so i'm wondering if thats normal for it to pop out like that? If it's not this then would it be the fuel pressure regulator? This is my first 'new' car with sensors and such so i'm still learning. It seems like the symptoms my buddies Cherokee had and it was the Throttle positioning sensor on that.