Nissan Repair: erratic idle, throttle position sensor, mass airflow sensor

Question
having a problem with my 2001 Nissan altima.  I have almost 62000 miles.  I have a jumpy idle when the car is in drive and my foot is not on the gas, sometimes the car will stall.  It started slowly, the check engine light would go on right after I would fill up the car with gas, around 7/8 to 3/4 tank then shut off around 1/4 tank, brought it to my mechanic, he check the lights and said that I need a tune-up.  got tune up, problem still happening.  changed idle air sensor and had a throttle body cleaning, still happening, now I am lost

Answer
Sal,

If you have replaced the idle air control valve and done a tuneup then I would be looking at the throttle position sensor and the mass airflow sensor.  Have these checked and see which is causing the problem.  These are the two most likely problems after an idle air control valve has been replaced.