I ran a diagnostics scan on a superchip and got the following codes P1280, P0603, P1316, P0470. I cleared the codes and then re-scanned and got the P1316, and P0470. My trucks Service engine light came on for about one second last Tuesday kinda missed and then shut off, ran fine. next day the same, until now it is on all the time and runs really rough. When i wiggle the drivers side valve cover harness the truck runs even rougher and then smoothes out when done touching it. Any suggestions? I am a pretty good do-it yourselfer. As far as the exhaust back pressure sensor where exactly is it located???