Hey! I'm new to this forum, and have questions I really could use some help with. I have a '99 GT, just purchased it 3 months ago. It does not run like a GT, for sure. I know I'm used to cobras, but this car is holding back. First thing, the idle is extremely irradic, sometimes going to 2000rpm then below 500rpms and dies. It only dies with the a/c on, but idle is always crazy. The engine is running real rough, too. We think it's the same problem? What weve done so far is replaced the fuel pump, fuel filter, and all the plugs thinkin that was it. Nothing has fixed the problem. Any guesses out there? Please help! Thanks!