i have a 98 avalon xl and we have changed the oil an filter every 3000 miles. we have been using regular unleaded gas. it now has about 50,000 plus miles on it. a while back the check engine light came on, so we went to the dealership. there we were told that because we used regular gas we needed to replace the egr valve and solenid for about $350.00. I don't understand why I need this when we were told that regular unleaded gas was fine. Has any body else had this problem. If you use premium gas over 50000 miles you will spend $300 or more just for the higher grade gas and I don't think they will guarantee you don't have to replace the egr valve. Despite the engine light the car runs fine. no hesitation or misfiring or anything. has anybody else had this problem and how did they handle it. It seems to me that this should be a factory thing and the consumer should not be caught on this.