Hi,
so i did a file for someone s passat, the car was already fine, working well, but the file i had prepared was for the "manual" soft, didn t know the car was automatic, so it didn t change anything to the car s power, and i decided to let it stay in the car while i would change the file.
I come back days later with a file and the guy says he noticed the car was smokey, even at idle, like when too much gasoline gets in or or too few air is in.
So i put back the ori file first, but it smokes as much.

egr is ok, after double check, the file is the correct ori file.
vcds gives a problem of cranckshaft sensor and a maf open or short to ground.

What could cause this to happen?

This is your problem - MAF open or short to ground. The MAF meter is dead so the ECU uses one single value to calculate smoke. It is around 550. At idle the engine can not pull so much air but the ECU still injects a lot of diesel so the car smokes. Check the MAF meter and the wiring cables to it.

ok thanks but i tried to run the car with the maf unplugged, the smoke was the same..

connect vcds and check airflow and boost + duty cycle of N75 .
I would suspect the air is blowing out from inlet .

the thing is it smokes also at idle

Probably I'm too late with this reply, but anyway...

Do you understand what RPMfreak wrote? unpluged = dead MAF = bad wiring in your case is the same. Engine/cylinders are getting more fuel at idle than it should, because ECU don't see MAF.

what kind of color is the smoke. white, black, white with little bit of blue feeling...that is important information.

this was white, excess of diesel