After i put my 408 i noticed several weird issues :
1- the fuel economy deceased 50%
2- there is a carbon smell when cold start the car
3- after 500 mile of changing the oil its color turned dark and it smells like fuel
4- too much oil consumption ( 1 liter each 1000 mile now the engine has 2200 mile) with no leaks or white smoke
and after fail in the inspection due to HC i called the tuner and he said it could be a rich condition when the car at idle or at lower rpm because it has 80 lph injectors (yes i put 80s because i have FI in my future plans )
so he recommend a tune calibration
now i want to know if the rich mixture could hurt the engine

 

yes, can wash cylinder walls requiring new rings

 

too much fuel in the oil will kill the bearings too

 

ohhh my God
do you think my engine is already hurt ?
if not is it a bad idea to drive the car for 300 mile to reach the tuner ?

 

is it a good idea to use flushing oil and to put new oil then to drive it for a new tune ?

 

I'd get a mail order tune of some sort before you start or drive it anymore! That fuel basically coats the cylinder walls and keep the oil from "sticking" to them. That absense of oil then, obviously, leaves metal to metal contact and too much friction and that's where the brunt of the damage occurs.