Engine's Misfiring

Prepare yourselves, I have a real question

I've got a 305 tpi with A/C and it's misfiring. At first I thought it was problem with the stock exhaust, which is too smoggy right now. What are the possible reasons the engine could be misfiring?

Ignition Control Module.. its under your cap and rotor, you can goto autozone or Orielly if you have one and have them test it for free to see if it's working, before buying one, to make sure.