Catalyst converter on an '87 ROW 930-20 engine?

[mauritsdb]

Hi, I'm new to this forum and am in the market of buying a 3.2 Carrera. A 1987 coupe (MY '88) that was originally delivered in Germany has caught my eye, but there are a couple of things in its paper work I don't understand.

The official Porsche birth certificate states that the car's engine is a 930-20 (Euro spec), but instead of 231 bhp, the power is listed as 217 bhp, which corresponds to a US/Japanese/Swiss 930-25 with lower compression ratio and catalyst converter. From what I understand, German cars could optionally be fitted with this engine to get a tax break, but this option is not listed on the certificate. The cars licence plate registration also says 217 bhp (160 kW).

Does anyone know if it is possible that a ROW 930-20 engine was fitted with a cat for the German market? And if so, could you get 231 bhp out of it by installing a cat bypass?

Any help would be greatly appreciated.