My trucks been sitting at about 300-400 rpm idling low even stalling once! ona hunch I unplugged the iac and the truck idles at 900 now. What confuses me is a bad iac typically results in high rpms, so in my case is the iac bad? And can I drive without it until I replace it?

 

How 'bout cleaning the plunger cavity with a bronze shotgun brush and mop? Maybe, while you're at it, scrub the cone shaped plunger on the IAC, reinstall and test it before dropping money on a replacement.