Mitsubishi Repair: 98 Galant, p0505 Idle Control System, vacuum leak, idle control system malfunction

Question
About 2 weeks ago I changed my starter because it wasn't working properly(wouldn't start all the time). Drove the car all day long(without problems), the next morning on my way to work my Engine light came on, I got it coded as p0505 Idle control system malfunction.

I'm looking to see if there is a way to single out that it's the IAC without paying for the diagnostic at the shop.  It runs fine with the exception that when I come to a stop the idle drops really low and 6/10 times it will die. When I restart the engine, the idle immediately drops so low it dies again. Only way to keep it running is stepping on the break and slightly pushing the gas.

The idle has been checked and it is still set right, can't find a vacuum leak so my last step is the IAC if I'm not mistaken?

Answer
Cory:You will need to go out and buy yourself a repair manual for your car. I work mostly on Eclipses. But in my repair manual, it tells how to test the IAC so that you can be sure that is your problem. If you had an AutoZone close by your area, they will code your car for free. But the repair manual for your car, would walk you through what you have to do to test this sensor and also if you have to replace it. Most parts stores have these repair manuals and they cost around $20.00 so well worth the money spent. It is a lot cheaper to buy the repair manual than get a shop to do this for you. I hope this helps and good luck! Linda