The dealer changed the plugs and put it on the tester since I described the problem to them when I brought it in. They did say it had an irregular spray patttern in the injector test and that was the reason for cleaning them. Seems like they would have burned me for anything else remotely problematic had they found something. Of course they did not solve the problem either. They did not change the fuel filter or mention any problem with the MAF but I see from other posts that those repairs do not seem to make a difference.

 

I spoke with a Lexus repair Tech this Am. He told me there is no way to test for a leaking injector or cold start injector without removing them. Also he told me the engine in the sc400 will experience some oil leakage around the valves. When it sits for several days this will cause the problem I described to him. He says they have seen it several times over the years he has been working on Lexus cars. Sometimes as few as 2 days will give you the smoke and rough running. It should clear up in about a minute he told me.
I guess the good news is you can start every day or so to avoid it, and there is a limit to how much oil is around the values to leak down when the car is idle.

 

I think I have this same problem currently on my GS. Did you do the replacement yourself or Todd did it for you? Thanks.