Thanks for the reply. This car is my 'weekender' so I don't drive it everyday, usually in the afternoons on the highway. nearly every morning I've parked it outside I've gotten a misfire and cel.
I still feel like the annual oil changes may have left some nastiness behind, so I'm going to take off the valve cover to see how bad it is. I've heard good things about Reslone engine treatment, so I may try that, or just increasing the frequency of changes to keep the detergent level up. I've been reading about the fragility of this engine's cams so if the lifters need replacing, looks like the dealer will be getting the pleasure.
meanwhile I'm ordering parts today to:
1) change crankcase ventilation valve
2) swap fuel injectors to see if code follows (already put in some injector cleaner).
3) change intake manifold gasket.
Then I'll clean the MAF, and call the dealer to get the computer re-flashed. I've heard similar symptoms being caused by a cam sensor, but I haven't seen any of those codes.
I'll post back with my progress.