1992 Buick Roadmaster Fuel pump. Or not

Our family truckster is having a problem. Driving down the road it starts to hesitate and loses power but doesn't do it all the time. I pulled the codes and got a 13, 44 and 54. I read that a 13 is a open fuel pump circuit. 44 and 54 is O2 sensor related. Does a fuel pump gradually quit or go out all at once? Somebody told me to check the ground also. The car also runs hot and we get a rotten egg smell from time to time. What should I check before I bite the bullet and spend the big bucks to get this fixed and is this a do it yourself repair? Any help is greatly appreciated. Thanks.