Hi. I have a 2003 Hyundai Elantra (5spd). I live in New York where all the gas stations recently started adding 10% ethanol to all the fuel. I noticed that ever since this happend my CEL (check engine light) has come on. It started sporatically (would come on and go off), but is now on 24/7. Two years ago when I went to get my car inspected, my mechanic reset all of the codes and the CEL turned off and it was able to pass inspection. This past year I brought the car to a different mechanic to have it inspected again and they ended up having to replace the whole computer chip. Before they replaced the computer they fixed my front exhaust line citing the "O2 sensors were the cause of the problem." I really don't want to have to replace my computer chip every year. Does anyone have any suggestions on what I can do to keep my CEL off? Incidently, I recently was involved in a collision that involved the front end. When I got the car back from the collision shop my CEL was off and I was very excited. Two days later it came back on and has been on ever since. I know that when they were repairing the car they had to remove the battery? When it comes to inspection time would it be beneficial to me to simply unhook the battery and essentially "reboot" the car just so that it will pass inspection? There really is NOTHING wrong with the engine itself.