Pontiac Repair: 1994 Grand Am Coupe, mechanic friend, fuel pressure

Question
I had driven my car and it stalled and wouldn't start even though it would turn over.  So a mechanic friend of my sisters replaced the fuel pump and fuel filter.  The car will now start and drive, but at around 45 mph it starts lurching and it will shift over and then at around 65 it gets really bad and chugs and when going up hill its like its losing power.  Tonite while driving it, it was lurching a bit while driving and then I lost power in my car for like a second and then it was fine.  I've read alot of stuff online and someone told me to try fuel cleaner and stuff and see if that helped and so far it hasn't.  Any ideas would be helpful.

Answer
Hi Mindy:

well it can be a few things either the engine is not "breathing" right maning it has an exhaust system that is restricted from a plugged catalitc converter or it doesn't have enough fuel pressure. I'd go the fuel pressure route first. this engine needs about 44 PSI to run if it's low maybe the new pump is bad or you have a wiing issue to the pump and the pump is not running as fast as it should.