I just bought a 2000 4runner and about 30 miles into it the light came on, I took it back to the dealer and he told me that if it ran out of gas at one time and now the light comes on at times. He also told me that he had it hooked up to a computor and it told him it was running a little lean. Is there a easy fix to this? I don't have a owners manual so I also need to know what the ETC button is. If someone could tell me it would be great, THANKS