Big car problems.

As I pulled into work today, my car stopped idling and had the tach bouncing around. It is breaking up heavily and will barely run. There is a rapid clicking behind the dash and the wideband is pegged full rich. I have already changed the igniton switch but it was an autozone cheapie. Being at work in a shirt and tie, I have no way of doing diag/pulling codes, but will be pulling it in the shop and working on it tomorrow. What I'm wondering is will a bad ignition switch have the effects posted above? The only time I had a similar problem, it was a bad coil and I do have the factory coil. However, I'm not sure if a bad coil would cause the clicking behind the dash..