I have a 99 Nissan Altima with a 5spd and I have had an issue where if I barely press on the gas pedal it will sputter for a second and then level out once I give it more gas. So I unplugged the IAT sensor, (I don't remember why exactly) forgot to plug it back in and my car ran great, just like when I started it for the first time after the engine rebuild. So I replaced the sensor, plugged it in and......the sputtering returned. So I unplugged it again and it runs great like before. I know this isn't exactly good so would anyone have any ideas on what could be causing this? My only idea at this point is to check the wiring but the more ideas the better.