You, sir, are correct! you already know a **** of a lot more than I did at 16. If the plug is white/ashy, that's usually normal. It does get hot in there... but if one's fouled up with either gas or oil, then something is usually causing it to be that way. You might want to check to see if you're smoking out of the exhaust after you change the plug.
Also, you can't get just one wire, you have to buy all six. Sux, I know. You need to get the right plugs for the SHO, it won't just take any plugs! You need to get Autolite double platinum plugs (APP 3924) or XP plugs (XP 3924) (my god, I've memorized that number, been around here way too long) for the engine to work right. NGK iridiums work, but will not last long. Bosch +4s are horrible with this engine, and will foul out quickly. Many spark plugs are too long and won't allow the wire boot to seal against the valve cover correctly, and will let water and crap in.
enough info for you yet? lol... also, you're also right about dumping fuel into the cats, it's quite possibly what was causing the popping as well. Raw fuel igniting as it mixed with the other cylinders' exhaust in the manifold and whatnot... definitely not good for your cats. They may fail soon, I'd keep an eye on them.
I think that's enough for now... just ask away if you have any more questions. We'll do our best to help you out!
