Fuel consumption B4

Hello everyone, I’m new here and I have to ask you something urgent: I bought the Audi 80 B4, Bj 93, 2.0l, 115 hp, approx. 140tsd km a few days ago. According to the owner, the vehicle has been standing in the garage for almost 1.5 years. Now I’ve been watching the tank display since then and I’m really shocked. Come with 22 liters of super only about 150 km!!!!! That can’t really be, can I? And I drive very restrained jetz at the beginning, just because of the long service life and stuff. if at the beginning after such a long time somehow has to “get in” again and then actual for (hopefully) short time a lot of about 15 liters on 100 km are needed? If not, how can I get this down again, there is a possibility besides the usual tips like ” avoid short distances”, “turn off at the traffic light” and “up in time”? Can an exchange of the lambda probe remedy? Or is there any other part that you could exchange besides the Motor ? Would be very grateful for helpful answers… Grüße Nikeeta