I've researched this online, but have not found any specific inquiries via a Trans Am. I have a 2001 Trans AM WS6 , and everytime I'm stopped and the car is in drive and just idling and I turn on the air conditioner, the whole car starts to shake. But, if I put it in neutral or in park, and turn on the air conditioner, the shaking/rattling of the car stops. I have read that it could be a host of things, from ( Spark plug(s) being loose, the Spark plug cables, to the Tranny or motor mounts or even the IACV or it could be a leak in the Vaccum ). If any of you can narrow it down or help me pin point whats going on, I really appreciate it. Thanks alot - Mike

 

Maybe, try the diagnostics/tune forum?
U have a diagnostic tool, such as EFILIVE, etc?

 

When You turn a/c on in drive sitting still does the engines rpm's get slower . How smooth does it idle with a/c off?

 

If it was a ls type engine in a truck I would try cleaning the throttle body and reflashing the PCM ......
But it's not a truck .. May still be the same fix though....,
... I work at a gmc dealership No to many f-bodies come in