Well the other day on the highway I noticed power loss and surging. I have the 04.5 lly engine. I plugged my diagnostic tool in which I had codes for egr flow insufficent and some kinda glow plug issue. Is there a way to disable the egr valve to see if this takes care of the issue? If the egr is stuck open im assuming it wouldnt make any difference even if the egr is the issue here.