Has anyone EVER heard of "Tuning Come Off Computers?"

I.E: Changing fuel maps and such?

My friend SWEARS that a tune is Guarenteed to stay on a PCM. That tunes come off and all the tuning you did is physically changed. I'm not talking about the way the car runs. GOing from hot to cold weather and all that nonsense. I mean physically re tuning the car because the tune you gave it... is gone.

Has anyone ever heard of that?

 

i think i understand your question and the answer is no, a tune flashed to an ECU will be there until it is reflashed with something else.

 

That's exactly what I thought!!

 

Your friend is referring to a piggyback computer... it can "lose" its tune especially in closed loop fuel control since the stock ECU is still the final arbiter when it comes to trimming fuel. It might even throw a check engine light.