Although timing isn't something I've checked yet, I don't see how anything ignition related could've caused a exxcessively rich condition. I don't see how the car could've jumped timing so bad to be idling as rough as it is. Car drove fine not too long ago. But to answer your questions, there was no corrosion on the cap and rotor. Yes it still has the cat. I'm gonna pull the codes first, should've done that first.
