My 2002 Avalon XLS with 130K has had a sudden loss gas milage. I used to average about 27mpg on the interstate...now I am getting only 22-25mpg.....inconsistantly. Around town has dropped from low 20's to high teens. It started about a month ago during a long trip up north. A couple of weeks ago we had more serious problems with stalling, erratic shifting and idling, unable to start plus the milage problem. Spent $800 on analysis that ended up with codes showing IAC module needed replacement. Car runs much better, but milage problem still the same. Only major work was fluid flushes and induction cleaning, brake job and timing belt replacement one year ago. Tire inflation good and there are no other usage changes. Tried some Lucas a few days ago, but no significant change yet. Getting ready for another long trip, and don't feel good about it. Planning on taking it back to dealer next week. Any suggestions?