For around $100 you can get a code scanner that readiness monitoring. That is it will show you which systems have gone through enough drive cycles to be ready to be read. In New York State you can have one system not ready to read and still pass inspection as long as the check engine light is not on. On my car the evaporitive system is the last one to be ready,as much as 5 days driving. If you are going to buy a scanner be sure to get one with CAN ( the next standard after obdII ) on it.