I have had the same problem with the stalling at stop signs and lights and like you said sometimes the car runs great and than other times it happens at every stop. I was told to clean the IAC also. I was told to do it with carb and choke cleaner. But I soon learned that it ruined the IAC and made problems worse. I didn't have a problem with stalling anymore. But that's only because it felt like the throttle was wide open and the idle speed was way up. It increased the speed all on it's own while driving. Stopping was impossible unless you put it in neutral and it only ended in overheating, spewing coolant all over the parking lot. So than I had to replace it, 70 dollars later, and it's back to dieing at the stops and now there's different problems. The idle is changing from low, (so low I have to keep revving it up to keep it from dieing), to high and back to low. So if I were you I would check the EGR first. I haven't had time to check and clean mine. So I couldn't tell you if that will fix it or not. But if it works for you let me know. Good luck
