2002 Buick Rendezvous junk Rendezvous

Electrical problem
2002 Buick Rendezvous 6 cyl Two Wheel Drive Automatic 81k miles

hi my car keeps stalling. When I am driving it starts to surge and chug until it cuts out. I have had it to the dealer a few times and they say no codes and it will not do it for them. I have had a fuel pump, map sensor, and a pcm. All have seem to fix the problem for a little bit but then it goes back to stalling. Please, please help me, I cant keep spending on the car. I have had it 18 months and spent 5, ooo on repairs. Any help is great. Thanks matt