My 94 ES300 AC works intermittently. After searching the forum for A/C information, I had the system checked and freon added along with a dye. There was not an apparent leak, so I'm supposed to take my car in periodically to check to see if there is a leak. The system worked great for about 2 days and then started either not working at all, or starting out by blowing cold air and then slowly turning to air temperature after 15 minutes or so. Does this sound like a problem with the expansion valve? Except for evacuating the system and refilling it, I will follow some very good instructions in one of the posts for replacing the expansion valve. I want to make sure that is the problem before I devote a whole day to this.