Well, I finished putting the van back together over the weekend. New intake gaskets, cleaned out the injectors, put a fresh spark plug in #5. However, all of that was well and good, but didn't solve my problem. Not only do I still have a misfire code for #5, but also on #3 now.

I think had put too much weight on the fact that the #5 plug looked like it had been lean and missed the bigger picture. If just #5 continued to misfire, I'd be tempted to think that maybe a plug or wire was faulty. But with multiple misfires, that's less likely. So where does that leave me? Got fuel, got compression, so ignition? Maybe the coil pack? Is there any way that a vacuum leak could be mistaken by PCM as a misfire? I'm taking wild guess here now...