Ok, I've been giving my 99 TL (107,XXX mi) an ongoing tune up for the last 6 months or more. I've had idle issues for a while now but in the past I was throwing and EGR code and Cat. Convertor code. I've since cleaned out my egr and replaced my cat and the codes haven't came back in about a month or so since I did the work. Also during that time I changed my plugs and somehow fried 2 coil packs which caused me to misfire and have random misfires and the six or so codes to go along with it. Well, I fixed that also (thanks to this board). But now I'm still dealing with the idle issues but my car isn't throwing any codes. My car alway revs at about 1000 to 1500 rpm's when I first start up in the am then it creeps down to normal after a min or so. But once the car has heated up and after being driven. If I turn the car off then turn it back on the rpm's drop down to 500 or a little less. it'll eventually creep back up to 750 where it should be. But this happens every time. Also, when the car is in gear I'm getting noticeable vibration in the steering wheel. The motor mounts were changed by the dealer at 99,500 miles so I don't think that could be the cause. Also, It seems like the car is trying to compensate for something by running a little rich. There is more "black" residue on my tailpipes lately. So what can some of you TL guru's suggest the problem may be.... HEY, I haven't found you all to be wrong yet!