Hi, my name is Cody, I'm new to the forum and this is my first post.

I have a 1999 Blazer that has been running rough for a while and is progressively getting worse. What I'm experiencing is slight hesitation when accelerating, rough idling and misfiring. When I'm sitting at a traffic light just idling my engine will misfire and I hear a sparking noise coming from the drivers side of the engine whenever it misfires. Also, when I turn my AC on, it gets much worse. I lose a LOT of power, more than normal and then engine misfires a lot more than when the AC is off. I tried replacing the spark plugs to correct the misfiring, but that didn't help, so that makes me think it's the Ignition Coil failing, but I'm not sure. I know it could be any number of things, but because I'm not a mechanic, nor am I very knowledgeable when it comes to car engines, I need some suggestions of what could be causing my engine to do this. Any help would be much appreciated.

Thanks,
Cody.