2014 Nissan Altima. The car had been doing it for a while it would sputter and drive rough for a while and then stall. The car does not start now unless you have the foot on the gas as you start it and then it just dies right after. I have a code P0171 which is lean bank 1. I went to AutoZone and asked for a fuel filter and they said its a nonservisable part. There are a thousand things that it can be. I'm thinking fuel pump but it says it also can be oxygen censor fuel injectors I just don't want to put a lot of money into it that I don't have to. How can I pinpoint it without spending a fortune? The oil level is full and the gas is on a little more than halfway.