Alright, i been searching on this but cant find anything but , I'm being told that you cant tune any obd2 ecu's or it very hard. My main problem is that i want to boost my car but stuck by emmissions, I'm from IL all they do for testing is check for faults and send you on your way. So if I convert to obd1 I wouldnt be able to pass the test. I would like to know the limitions of these ecu's , Why can't you tune on them? all I can find is that its hard or you can't, so if you can give alittle more info than "its hard" it would be greatly appreciated, I would like a better understanding on this topic. Thanks.