Carina E Sportwagon 1.6 Mini Cat

Hello together, I bought a nice and practical Carina Sportwagon on the weekend, with everything around it (even heater). Had informed me about this car here before extensively, great forum here. Is a Japanese, has zero rust, completely dry, all maintenance work done (including brakes), battery new, climate maintained, only 112000 km, top in shot, however red (you can not have everything). Unfortunately, the car is only low in pollutants E2. In the papers I have thisbzgl. Encryption 14, which is tax-equivalent to Euro 1 🙁 On the Internet are offered mini-cats, also for the carina, but with different strengths. So that I take the right diameter: does someone know here which diameter the exhaust system of the Carina E Sportwagon 1.6 4E-FA Bj. 11/94 has? Thanks for information!