Re: How to make out a BS III engine from a BS IV engine Thanx for info. Then why my dealer do not select the option of BS-3/BS-4 while scanning the ECU of my car. :confused He directly selects FIAT then PUNTO LA & after that Magnetti-Marrelli 1.3 MJD Injection System. Then he clicks "CONTINUE" . After that home page of scanning comes. I attached ECU scanner for about 15 times in the 16 month ownership. Nobody might have not connected examiner to his car for such no.of times : In ECU Examiner I did not find seperate option for BS-3 OR BS-4 cars. & most important on my qtr.glass FIAT had mentioned BS-IV.