It depends on where they introduced the cleaner and how thoroughly they cleaned things. My experience is that the throttle body usually needs at least a light brushing to get clean. I use an old toothbrush.
The IAC will most definitely effect both the idle and light thottle operation.
Pull the air intake hose off and have a look at the throttle body. I'll bet that it didn't get cleaned very well.
I'll I'm saying is review the work that was just done.
