Dies when i slow down....

Hi all. I have been having trouble with my 2000 Camaro for a while now. At first it was dying on me if I was at a stop light and i went forward a few feet and stopped. Now it is dying on me whenever I slow down for a stoplight or to make a turn. I have changed spark plugs, spark plug wires, the Mass Air fuel sensor and cleaned fuel injectors. I talked to a mechanic online and he said that it looked like the Idle Air Control valve was out but come to find out, I dont have an IAC valve for some reason. I have a 3.8 liter 6 cylinder engine. I am at wits end on trying to figure this thing out. Any help would be greatly appreciated.
Maybe I do have an IAC valve but I have no idea where to locate it. Im lost. Thanks for any help.

http://shbox.com/1/iac3.jpg there it is on an LT1(v8) its on the underside of the throttle body.... so im guessing it would be in the same place on a v6

This might not be it. But in an automatic when you slow down it doesn't down shift quick enough so that the torque-converter will stall the engine much like a clutch.

change what is called the lock out torque converter switch or just unplug it from the transmission the only thing it will do is start in drive gear where now it wont just unplug it and it will stop stalling at slow downs or stops

Thanks for the replies. I will check under the throttle body to see if the IAC valve is located there. If not, i will try the torque converter switch. Am I wrong by assuming that the IAC valve should be on every Camaro engine? One mechanic said it did'nt exist and I don't see why it wouldn't exist on mine. Just wondering. Thanks again.