Hyundai Repair: Idle problem 2001 Elantra, air control valve, rough range

Question
The idle on my 2001 Elantra wants to run at high level when in neutral or park.  I have replaced the throttle control sensor, as the check engine code indicated, and the problem still persists.  Will replacing the idle air control valve solve the problem?  

Answer
Hi, Joseph.  Unfortunately, trouble codes sometimes don't indicate the component that's causing the problem.  Although manufacturers try to make them as helpful as possible, the computer logic that causes a particular code to arise causes the code to be misleading.  

Although it's possible that the idle control valve will cure a high idle issue, it's likely that the cause is elsewhere.  You might try checking the PCV hose to be sure it's not leaking extra air into the intake, causing the high idle.

I'll have a better understanding of what's happening if I get a few more details.
1.  How high does the car idle?
2.  Does this occur all the time or only on cold starts?
3.  If only on cold starts, what is the rough range of air temperatures?
4.  What was the actual code number that was stored?