P600 but it is a MT5 speed
 

I need your opinion.

It's a 2000 2.7l boxster 5speed MT. The vehicle is slightly underpowered, there are no stored faults (apart from one). The only fault is a

http://986forum.com/forums/uploads02...1732461592.jpg

We have verified the Durametric with PIWIS, only this error remains. We discussed this and one idea was that the car may have been mapped for a tiptronic some time ago. This would explain the fault and possibly the underperformance.

What do you think, is that plausible. Should i just install the correct mapping? What are the risks?