I happens while in traffic or at idle.
Not always but maybe evry other day once or twice.

It starts inmediatelly though

If it was a carburated car I would have rised the idle.

Any ideas what can this be?
Already used injector cleaner and nothing.

 

Maybe MAF sensors. Check for fault codes.

 

If it was the MAF I should get a check engine light, correct?

 

Not necessarily, I once fitted el cheapo MAF sensors to my 04 CS without knowing it (they were fakes, marked as "Bosch"), anyway they worked for about a day, then the car readapted itself to the new sensors and then she refused to start ! There were no fault codes or warning lights. I put the old ones back in and all returned to normal.