Ive got a check engine light on so i did the key dance. Came up p0404 EGR valve. Could this cause the chugging, we do run a ethanol blend in the van but not ea85.
What size engine? 3.8? is the pipe on the left of the engine going from the left side of the head to the top of the air plenum by means of a metal pipe? I don't know what effect ethanol could have on these. The removal of the egr is not that difficult, a few bolts. If that is the problem. It may need cleaning. I have taken these apart and cleaned them, but not this model.
Yes a bad EGR can definitely cause rough running and poor acceleration if it's stuck open.
Ethanol shouldn't cause any rough running but may cause a loss of economy.