Why is my toyota echo getting bad gas mileage all of the sudden?

My 2005 toyota echo is using up more feul now than ever. What could be the problem? there doesnt seem to be any issues that are apparent to me. Anyone have any ideas?Why is my toyota echo getting bad gas mileage all of the sudden?If it happened right after routine service, the rear brakes may be overadjusted. Some Toyota techs seem to do that a lot.Why is my toyota echo getting bad gas mileage all of the sudden?Change the oil maybe? I know when I do that in my truck it always gets a little better.Why is my toyota echo getting bad gas mileage all of the sudden?get it scanned for failure codes, and you may have the answer.