2000 Honda Accord 2000 Accord engine surges at idle and at

I have a 2000 accord lx v6 that will not run smotth. It starts fine but immediatly the engine starts to surge up and down. I f Itake up to 3000 rpm it surges up and down. Like there is not a staedy fuel flow. When I bring it back down to idle it surges up and down and will die out on the down surge. I have replaced the iac vavle and the egr valve and coolant temp sensot and the throttle body with another tps and the map sensor. After clearing the codes the only code I get is for the map sensor. After checking the sensor there is a problem with the wiring somewhere between the pcm and the sendor. I have checked the wiring as far back to the wiring harnes as I can and did not find a short. But my question is can the map sensor fault be enough to cause this much of a major problem? The vehicle is not driveable at all. I guess I need to have some advise on how to eleiminaste anything that it might be from someone with knowledge on how these hondas work. I am from the old scholl where it it either fuel or electrical that caused the problem. Number 1- Is the map sensor fault enough to cause this kind of problem? Number 2- What else could it be and how do I diagnose what it might be if there are no other fault codes in the pcm/
Thanks