could this be an alternator concern, a coil-pack replacement or perhaps air intake lines?

have replaced fuel pump and injector, battery works good, have had the service personnel complete a computerized diagnosis (couldn't find a problem); however, I continue to have idling problems, SUV stalls and/or stops when idling, noticed the other night when using the electric window button that the headlights dimmed, this morning a continuous beeping sound was heard when the vehicle was started .. after 20-30 minutes of continuous driving these concerns disappear and vehicle runs fine.