I hear you are the person to speak to about my Avalon issue. I have a Federal Emissioned 1997 Avalon with a P0125 code. I posted in the first generation forum and listed all the things I have done to this vehicle but to have this code still show up about a mile into driving. The weird part is it shows up at higher rpm's which is leading me to a vacuum leak? I drove the car on my property at slow speeds for :30 minutes after cleaning the throttle body and the light did not come on. The next day I took it out on the road and about a mile away, the light came on. I am at the end of my thinking as to what it could be. You being a Toyota mechanic might know what has generally gone wrong with these first generation Avalon's.