My brother got this truck around christmas... all was well for the first few weeks, then it started to cut off when stopped in drive. A few people told him that it was the fuel filter, so he took it in to have that done and to have everything checked out. After that it seemed to be better, a few weeks later it started again and it has done it ever since, he has never had it looked at about that again. Lately it has gotten alot worse to the point that sometimes it cuts off when braking and he has to keep on the gas and brake to come to a stop, I'm sure it will be in the shop soon, and he wouldnt work on it himself, but does anyone have an idea as to what is causing this? Thanks

Jamie