my car idles very rough at 500-600 when (warm) if it is in drive. it feel s really wierd and makes me mad. i had it tuned up about 5 months ago. now it just started to do this its driving me nuts
can someone tell me where to check for vacuum leaks and wear my IAC exactly is and what it does and what could be my problem

 

It is [robably your intake manifold gasket. I had the same problem on my 3.1.
That is just a guess though?

 

i was thinking some sort of vacuum leek cheak it all man hate those leaks