Can someone please help me out. I have a 1997 Buick Park Avenue. 3.8 L V6 with the Supercharger. I am trying to get this vehicle to past inspection. The check engine light is on so I had the code read. It's saying that there is a Cylinder 4 misfire detected. I have replaced the wires and plugs. I am almost certain that it is a bad injector but I don't know which one. How can I tell?