[sierrap615]

i doubt the lowering kit is affecting this.

if you have never replace the ECT, you may want to look into it, you can search this forum for countless drivibly problems it has caused in the past. replace only with the new brass tipped design from a saturn dealership.

also the IAC may be binding, which can be caused by internal binding where it would need replaced or external binding which just cleaning it may work(more common). remove the intake tube to the throttle body, check for carbon build-up, the IAC is inside the hole beneth the throttle plate. try cleaning it with carb and choke cleaner.