Bucking. Misfire Code. Smoke. Fuel Odor. I need help.

So my RAV has been missing on occasion here and there for a few weeks. Finally it began missing like crazy. Jerking on acceleration in low rpms. And then a check engine threw out a misfire code on cyl 4. It also smoked like a train, and I could smell fuel when I started it the next morning.

I pulled the plug and sure enough it was fouled. I replaced all of them while I was there, as well as distributor cap, rotor, and wire. It drove better, almost no misfire, but the next morning it smoked and had a fuel odor again.

Any thoughts on what might be going on? I believe the misfire may be causing the plug to foul and get worse over time. What is causing that?

My daughter is the usual driver. I had the chance to get a good take on it today. Over the last couple of days it is bucking badly in the morning and smoking after a couple of minutes driving. Once hot, the smoking and bucking decreases or stops. Today, it was pretty bad and the smell of fuel was strong. There also seems to be fuel leaking onto the block. Could this be as simple as a bad o-ring from the FI? How labor intensive is that? I have the Haynes manual, and just enough know how to get me in trouble. It's parked until I work up the gumption to tackle it. Any deeper thought or input is greatly appreciated.

There also seems to be an oil leak around the valve cover gasket. Perhaps oil has penetrated the wiring? Ack!