1998 V6 Chevy Camaro Problems, Please Help

I have a 1998 Chevy Camaro V6, which had some problems lately. Recently, when I was starting from a complete stop it seems as if he would have difficulties. It seems to jerk back and forth, and once it goes off, its fine, it has to speed not much power. Also “rattle” when it idleing. I have recently gone to Auto Zone where they offer a free report / test, and bought himself a recognized part one, which was not emitting a spark (“cylinder misfire – replace cylinder Random” – We replaced the ignition coil for 2 + 5 Since it is not emitting a spark when the engine was switched on). Thinking that was the problem, we tested it again with the test / report device, and it passed. When I store the car parts, was the check engine light on, and flashed, then told me the problem was not resolved. I also hear a strange noise while the car is running, in the rear of the car, and I thought it will be the catalyst. Help! What powers the ignition coils? Is this perhaps the problem? The car has 62,000 miles on the Tacho.Wir remove the plug wires from the second coil, neither had run a negative impact on the way the engine. We think that either the ignition coil was bad, or what supplies the ignition coil is falty.