I'll probably check the coils and for the oil leak. I already repaired the leaky vavle cover gasket twice! One thing that worried me, though, is that the connectors for the coil wiring harness were brittle at 30,000 when I first changed the spark plugs. They broke, but still seemed connected well. I may check that and just solder them on. I'm leaning towards the vacuum leak/electrical connection theories, since there is no CEL. Does that make sense?

Thanks,
Kris