egr valve & codes

The code for the EGR Valve has been off and on for about 1 year. I never had problems with it so I haven't worried about it. But for a couple of weeks now, It misses, cutouts, and hesitates and even when it idles it cutouts slightly but never dies. I wanted to know if that was the EGR valve or if anybody had an idea. I experienced almost this exact problem before and it needed plug wires. It ran well for almost 6 months thats why i am wondering if its the EGR valve or a problem with the plugs or wires.