My truck is all stock except I have took off the muffler and straight piped it after the cat with 4in. for about 3 ft and dumped it out the side. Tuesday we had a big snow storm (about 14in.) and I had to make an emergency trip to town (15 miles). All the way there and more so on the way home I was busting thru some pretty big drifts. The truck was doing excellent until the next morning I fired it up and the CEL was on. Any ideas?? It goes to the dealer on Monday. Not sure what they will say about the pipe.