Conversion from E1 to E2

……somehow I need your help. I have been offered an Olsdmobile Cutlass, year 1994. The Olds has a 3.1L machine installed. The one has EURO 1. Is there perhaps a way to get such a vehicle somehow to EURO 2? He has, although he was already on German roads, “only” an American letter …..so no German. Then the last inspection was according to maintenance booklet in 2008. Is there something like that???? …… I thought that i The car drives, but when braking, the electronics start spinning around, the gears change and the engine goes off. What can be such a thing? I would be very happy about helping people of this forum. Thank you very much!