Audi 80 1.6e Covalue too high.

Hello colleagues. ICh has finished an Audi 1.6e Bj 94 for a friend Tüv. But: I raced through the Au. The Co value was way too high. Lambda was ok and the car runs normal in my opinion. Although it went out once when the fan went off. It is weak on the chest, but I don’t know if it’s true. It turns normal but does not set out to idle sounds normal. Nevertheless, Co value too high. If I hadn’t made the Kat new, I would blame it. Can it be that it’s due to a Temp dealer? Someone knows the supposed resistance from the coolant temp. Giver around air temp. encoder I really depend on help because I have already designed over 500€ and the car should run.