Do I need the preheater???? will pulling the fuse damage any other part??

Does anyone know if there is anything I can do about My Landrover Beker sat nav radio I can only tune it to odd numbered stations ie 98.5 but not 95.8 help!!!:confused:

I also have just bought a 2004 HSE TD4 auto Freelander and I am getting the real gas smell in the cabin if you have the windows open however with the aircon on it goes away it seems to be coming from the wheel arch can anyone help have seen the coment about the preheater is this fixable