Originally Posted by rbabos
TTS is a flash tuner, not piggy back.
Ron is correct, TTS Mastertune is the evolution of the SERT (both flash tuning products that modify the calibration parameters within the Delphi OEM ECU).
My personal favorite for that route is the PowerVision unit with the TargetTune module (wide band read outs on the handle bar with full time closed loop is an excellent thing to have when you get deep into tuning).
FYI: Forget that terrible "vendor" like a bad habit. He's a miserable guy and spouts garbage as gospel. I imagine a crochety 70 year old in a garage with dust around him cussing all day. I know a local engine builder near me who is identical in behavior. His shop looks like a dust covered museum of the 60's as well. Good times.