Nissan Repair: 2002 Nissan Sentra GXE Bad start, obd2 scanner, obdii scanner

Question
My fiance's car is starting very badly at times. Sometimes it starts and it idles aroudn 500 rpm till it picks itself up to aroudn 1k rpm. Other times the engine turns and turns and turns . During these times she presses down repeatedly on the gas pedal and eventually it will start up and run. I've changed the spark plugs (NGK). I put my OBD2 scanner and it is showing the TPS opening and closing when your pushing/releasing the gas pedal. The Haney's manual says to bring the car to Nissan to check the IAC. Do you have any suggestions or recommendations for our problem???? TY

Answer
Feller,

Either the idle air control valve or the mass airflow sensor.  If you have an OBDII scanner and you are reading no codes and it is only doing strange things at idle I would think the mass airflow sensor since the car is known for these going out with no codes.  But, at a steep price I would have it scanned prior to purchasing one.