I believe gt1 has the most options but not 100% as I ordered that one but haven't gotten it yet. It will allow you to actually flash the ecu on top of coding, live readings of codes and stats(battery,a/f ratio/battery/etc). As for just a cable eBay would be best. Sorry don't know too Mich on all the tuners/coders readily available and I think depends on year/model as well. Please correct me if I'm wrong about anything and I recommend searching before making a decision as I'm sure there are pros and cons to all. Hope this helps a little bit?
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