Since ECU flashes typically take into account mods done ot the car to make it breath better, what happens when you go back to stock? Is it going to run more aggressive profiles when the car no longer has the mods to give it the air, etc. that the ECU is asking for?

Will a modded ECU work well with the car stock, i.e. if you were going to sell it?

 

Most of the time you will need to reflash the ECU back to stock specs.

 

I actually had the full TS Crawford tune done before I had my Crawford headers installed. Car ran like crap and 1/4 times starting it the Check Engine light would be illuminated. My best guess would be it was getting knock? Dunno really what was causing it. My gas mileage was pretty crappy too. Soon as I got the headers put on the car felt much better, CE light never came back on and my gas mileage went back up a bit. Pretty sure if you left a tune like TS in with everything put back to stock, the car wouldnt be too happy.