do you have to have a piggyback or fuel management system to go to a dyno and tune your air/fuel ratios, or can they tuning shop hook up right into your ecu?

 

You need a piggyback unless you go to Technoaquare, where they will reflash your ECU.

 

but what if i get mods after i get a reflash because i would get mods over time but i dont want my **** to run bad or not right

 

With a reflash, you have to get it reflashed after every change you make. Well, you don't have to, but for maximum performance, you do.

Same goes with tuning, except you take it to a shop and have them tune your programmable unit, i.e. Greddy eMAnage, UTEC, etc.

 

Yup, that's why it's best to get all the bolt-ons you want and tune the ECU LAST.