Hello,
I have another thread on here about my '92 Camry V6 XLE that stalled while driving 55mph and won't restart.
http://www.toyotanation.com/forum/t86211.html
In trying to diagnose the problem and check for spark, I found a bad plug wire on the #2 cylinder. The other wires were fine. When I tried pulling the #2 plug wire out, the wire snapped inside the hard plastic sheeth that runs through the valve cover to the plug which is how I realized the wire was bad. I pulled the broken wire piece off the spark plug. I peeled back the wire jacket and insulation on both ends of the break, and the thin black core wire was rotted away (there was a bluish green crust in there). So, I know that the core wire was good and didn't just somehow snap and went from good shape to bad in a hurry. The car never acted like it had a missing cylinder until the last 5 minutes of running before it stalled. So I'm thinking the wire was still firing somewhat until it's last few minutes of running, that or the Camry V6 just runs really well on 5 cylinders and I've been too stupid to notice. I have plenty of exprience on the pickup/4Runner V6 and 22RE 4 cylinders, and it's quite noticable when those are running minus one cylinder.
I'm starting to wonder if the wire has been slowly failing and the unburnt fuel from this cylinder ruined the cat?
For what it's worth, I've checked for spark, fuel, timing belt, injector resistance, fuel pump operation, replaced plugs and wires. Now, the only two basic things I haven't checked are fuel pressure (I don't know what kind of tool to get besides the factory Toyota tool), and air flow. My other post goes into more detail about what I've done.
If it's got fuel and it's got spark, then the problem must be airflow?