Originally Posted by olddudesrule

Look, I've lived in two states with pretty stringent emissions laws, and had "tuned" cars in both. As long as you don't have a CEL on, and all emissions systems show "ready" or "run" on an OBDII reader (which you can check youself)' you should be fine. They will be looking for a CEL or monitors that are not showing in run condition, that's it. A tune will adjust your fuel trims, and can also be used to turn "off" certain things (like the CEL for down stream O2 sensors), adjust your fan on/off temps, etc...