to reset your base idle you need to get the system to go into diagnostic mode. hook scanner to it, turn key on, once scanner has connected and is talking to ecm/pcm fans should come on, this tells you its in diagnostic mode. unplug the iac motor/valve. the iac should be closed. now start er up and set your idle at 400 rpms. turn key off and plug iac back in and restart. it will take a few runs for computer to adjust.