Im attempting to tap into my odb to see some live data to help diagnose my fuel economy issue. My vehicle is a 98 jeep cherokee with an iso9141 female plug. Now i have a iso9141 to usb cable that was used on a friends audi. Ive been using freeware to no avail. I assume that my interface is not compatible with the freeware that im attempting to use since they all say elm and this is not an elm interface. My questions are

1. Is most software only compatible with the elm chip?
2. How do i find software to work with the interface i have. I know my friend used vagcom
3. If i need to purchase a scantool, i would like one that will work with all vehicles including the new can stuff. Which is best?
4. Am i stupid