There is nothing mechanically wrong with my Boxster S. However when I try to accelerate, the car just automatically decelerates when it reaches around 25 mph. I believe it is the MAF sensor, but I am not really sure. I can never reach freeway speeds because of this limiting problem. It also does not go above around 3000rpm. Any help would be appreciated. I see a lot of people are viewing my topic, however are not responding. please help

fuel filter?

This sounds like an exhaust problem. However, your post is old and this forum is moribund