OK, this is what happened. Blew a heater hose and decided to replace them all at once whilst doing a tune-up for good measure. Removed the intake manifold to facilitate all the work. New cap/rotor/plugs, wires are about 2 years old (Bougicord) so they stayed. Didn't clean TB since a visual inspection showed no signs of crud. Flushed breather box and attached lines. Flushed IACV. R&R ALL coolant hoses except for hose below oil filter since it is only about 2 years old (all others were original). Put it all back together and drove to Florida (300 mi). At about 200 mi. I notice the engine occasionally missing at idle when stopped at a light. It worsens over time, the longer I am at idle, the worse the miss(es). It gets to the point that it continues to miss even as I accelerate, then fades away to normal operation at speed. When idling normally, I am pulling 17-18" of vacuum, it drops to 12-14" when the misses begin. Car has not actually stalled but has been close. None of this occured before my aforementioned work.

I guess my next check should be the injectors since they have never been serviced and the car has 200K (due for a flush). Is there anything obvious I am missing before I pull the injectors? Oh, I'll be checking the OBD when I get home tonight. One last thing, there does not seem to be any connection with engine temp, it does it when both hot and cold.