Just saying hello cause I have to.. So ive said it. Thank you very much.. I've got a '94 Z28 A4 with the LT1 of course It's got 128K on the clock changed the head gaskets 2 years ago right after I had done a full tune up including installing an MSN OptiSpark plugs wires new water pump new radiator all the hoses all the water and vacuum every single component involved with the ignition system was replaced needless to say she runs like a champ for the most part got a bad air pump right now I put in a 160 thermostat after I changed the head gaskets and that's why I'm here I want to change some of the settings in the computer to a more accurately reflect how the car is set up now. And after Ive added certain bolt ons . I have an old OBD1 scanner that works great and I also use ALDL Droid on my phone. It seems to work great. I have yet to use it to program anything but it looks like and says it'll do the job so I believe that it will. Lastly I have 94/95 Free scan on my computer. I don't know if that'll help me with changing the codes but it lets me see was doing.. I am a complete newb at this and I am learning as I go any words of advice for much appreciated and will be taken into consideration always. I absolutely love my car and I'll do nothing to harm it so anything I do with the computer I will have quadruple checked and then quadruple checked that again before I do anything It's just how I am I'd rather be safe than sorry you know.