Code PO171, mulitible possiblities for repair
1998 altima, When car heats up has rough idle, engine light comes on and off, code PO171 comes up, says it can be oxygen sensor, fuel pump, fuel pressure regulator, air mass meter, leaky air intake, fuel injectors. changed oxygen sensor (front), light came back on, although car seems to run a little better.
What are the usual components in this case that fail.