I cleaned my IAC and that cured the little bit of bogging I had, but that doesn't really explain your change with going to straight pipes. Unless its just a coincidence? It's pretty easy to clean. It's attached to the throttle body on the firewall side.
Yup, I cleaned mine with throttle body cleaner. When I cleaned it, I kept the end with the wire connector up high to make sure I didn't get it wet. I also used a Q-tip, but make sure you don't leave any Q-tip material inside.