I had the same problem I think mine popped off while I was playing around on the dirt, coincidently, on of the hoses popped off from the egr valve. I was freaking out because it was just around the times I had to get my OVU smogged, I checked it after the great advise of a few of the members here and it went back to normal, after I clear the code for the last time, luckily I didn't have to buy another egr valve .