I just recently bought a 1999 sportage for my wife, and it was having issues of really rough Idling when coming to a stop light. It would not die, just idle rough. As soon as you got going around 20 mph it cleared up, and ran fine. This was driving us nuts!
I went to auto zone, and the guy there put the code scanner on the plug under the steering column, and said it had 5 error codes, and he would print them out. He did, and I went home to try to figure this out, from looking on this website, and downloading schematics from KiaTechInfo, etc. I got nowhere real fast.
The next day, I went to Advanced auto parts, and talked to a guy there who knew what he was doing. He is a mechanic on the side, and a parts sales guy by trade, and knew exactly how to use the code scanner. He looked at it for a couple of minutes, and said, "you have too many conflicting error codes in here", then he cleared the codes, and had me start the engine, and he rescanned for codes. This time it came up with two codes pointing to the mass air flow sensor, of different types. He said "your maf is not working right", and typed in several quick keypunches and looked at the realtime maf operating parameters. He then said "see how it is reading 25%, you should be at half that value, around 10 to 12% while idling", and then unplugged the maf sensor plug. Nothing changed, it just kept shaking and idling rough. He said " that should have caused it to die" and plugged it back in. We went inside to see if he had a new maf,and he said he would have to order one. I told him I had to get it fixed today, thanked him for being so nice, and went to our local pick and pull, and got a maf off of one there, and installed it in the parking lot. Guess what?? .... all of the shaking, rough idling stuff went away, it ran like a top all the way home, never missed a lick!! And it has ran good ever since.
The only weird thing it has done is one time when she stopped at a light, it revved up real fast by its self, and I am thinking maybe there is a glitch in the throttle position sensor or something. I think I need to go see the guy at advanced again, and this time maybe pay him a little something for his time he put in helping me.
All in all, I love the little sportage.