I hooked my ODB2 machine up to it and got nothing from it. It wouldn't connect to my car's computer. I'm wondering if there's a certain type or brand I need to have in order to read the computer... or if its a different type of system?

Also, my Diamante has 143k miles on it. It runs fantastic and have no complaints, but sometimes when its hot it will chug chug chug when I start it. Is that the thermostat, or would that be the EGR valve?