I have 1997 ES-300. I just came back from the dealer. My Check engine light came on and Track Off light came on after a couple of days. The dealer said that my Charcoal canister is faling apart and the hose is internally clogged. Bothe need to be replaced. Estimated cost $503.80. The part # for canister is 77740-33062 and for hose is 23829-20011. I found the part online at newlexusparts.com for $218. Could not find the hose online but my guess it would be $5-10.
I also had an issue of sounds from the rear end when the car goes over bumps. My lexus dealer fixed it today for $100 by replacing Stabilizer bushes (Parts $30, Labor $70).