I bought a 2003 350z automatic 5 speed transition 2 months ago with around 130,000 k miles and it now has almost 140,000 k miles. It just started giving me this problem of stalling to the point where it won't start the first time, giving me under 1k rpm, when I turn the ignition. None of the warning indicator lights turn on except the low oil light on rare occasions that i make a sharp turn. I've also noticed that the oil gauge is low when i take it out for a long drive on the freeway but is at 30 when I first turn it on; not sure if these two are correlated though. I tightened the battery bolts and it worked for a little while but it's doing it again. I'm going to try cleaning the throttle body and relearning the ECU.

 

OP-
If the plugs have not been changed you are way overdue. Check at least 2 before attempting the processes you mention. As far as oil pressure, the sending units and sometimes gauges aren't accurate. This is a 16 yr old car. Make sure your dipstick indicates "Full" at all times. The oil pump is designed to last the life of the engine, assuming correct interval oil changes.

 

If your car is telling you your oil is low and your oil pressure gauge reads 30 on cold start up, I would suggest you immediately check your oil level. My oil pressure starts at 90 psi cold and goes down to 30 psi when completely warmed up at idle.