You know this thread is funny. You know that doing it the way you are thinking could cost you a ton. Don't you have an auto repair shop that you feel comfortable with? I thought I saw an earlier thread that told of the good repair shops in your area. What a lot of folks don't understand is that the scanner will give you a code. It only tells you the area of the problem. For example the evap code for a loose or leaking gas cap is the same code that can come up for a leaking intake manifold or other leaks in the evap system.
A good way to handle the problem is to spend your time looking for a good repair shop and working a little harder at your job to make the money to pay for the repair.
Being an old man that has been through these kinds of problems, I have a good electrician, roofer, plumber, and AC guy to turn to.
Papaw