Flawlesz

Bought the car in October '12, 56k, CPO, seemed to run great. A little while after, is started to idle a little rough. I could feel it in my thighs through the seat of the car. It started to get a little worse. Now I am really noticing it (head games, but its definitely there). Also, MPG has gone down from 23 ave when I bought it to 20. I just averaged my last tank at 18.x mpg when I figured it with a "trip/gallons to fill tank" calculation, and I've been consciously trying to get good mileage, however its been snowing lately which can affect it. Thought maybe new plugs would clear it up since I'm at 60k. Just did plugs two weeks ago, and it's still idling like this. If I hold it at 1000rpm, or just above idle, it is fine. This is literally the symptom: at idle it starts to build slowly getting a little rougher and then goes away, then a second later it starts to build up again, then goes away. Repeats continuously until I go.
ALSO, found this on the service history for my car at the lexus drivers site:

09/02/2011 ALE REPL COMP SPRINGS & LASH ADJUSTERS FOR IS 350

Is that ^ that valve spring recall?

SO, IF that's the recall and I've got new plugs, oil, filter, etc from 60k., then whats goin on?
I did the work on the 60k myself, but had them do brake fluid and their complimentary lookover, they didn't see anything, though I failed to mention the idle because I though plugs may clear it up.

I'm going to call the dealer tomorrow but want some suggestions first so I may know what to ask, or look out for.

Thanks for any help and feedback.

Flawlesz

I will also add, that I am going to take it over to my shop tomorrow and check for vaccum leaks, or anything abnormal. I doubt this is it, since I just did work on it myself, and the dealer also looked over the car. I will look again anyway.

slideland

A good way to start diagnosis is a visual inspection. Before you open a can of worms check the dealership with your vin to make sure it did infact get the valve campaign. Its a free call. Then look for the obvious. (for instance cracked spark plugs or not seated coils)After looking your car over empty your gasoline And put in proper octane(93) fuel from a reliable source. Then check back in.