i have a 99 gt, i believe I have a bad coil. when the car is cold it will run fine but after 5-10 min of running it begins to have a horrible miss and is really hard to drive it may even be more than one coil. my question is how do I go about testing the coils. I know i could pull the coil and crank the car and look for spark but obviously it is still working to some degree so I do not think that would give a very definite answer.