tuning file
 

when you rest the ecu of the car does the tuning file get affected in any way ?

I presume you meant "reset" instead of "rest." If so, when you reset the ECU (typically by removing power from the car for an extended period of time) the fuelling trims learned by the ECU are reset. Other learned values are also reset.

The base code for any given map is not affected by power loss to the ECU.

I just saw your other post about cleaning the MAF sensor resulting in a perceived loss of power. I presume you are trying to troubleshoot this by resetting the ECM. You can certainly try resetting the ECM - it won't hurt anything. My advice to you; however, is that immediately following the reset, turn the car on and don't move it for 60 seconds. If you immediately drive away following a hard reset, you can force the car into a limp mode as it hasn't had time to set a fuelling trim baseline. Limp modes make the car accelerate sluggishly and can take some time (dozens of miles of driving at various RPMs) to reset. If you let the car adjust to idle timing, your chances of going into a limp mode setting are reduced.

okay ty