I am thinking about getting the interface cable between the OBD2 port and my laptop. Can the stock ECU be tuned? What I am looking to do is get more mileage out of my ride (for now) and also have the ability to check codes, etc. on all the cars in the family. I want to upgrade and do some tuning on my ride but that is in the future. I am trying to learn as much as possible about tuning but if I can't do the mileage improvements needed, I'll just hold off on buying the cable. Please share your thoughts, as I don't know nearly enough about tuning ECU's.