When I drive my discovery for more than an hour on the highway it wants to stall or it won't go any faster. It feels like I took my foot off of the accelerator. Then it will work again for a while and it will come back again over and over. Does anyone know what this is? I'd rather not take it to a dealership and pay a whole bunch.

 

its your vehicle speed sensor (VSS)...its bad....get a new one, or have it replaced