My dodge ram 2002 truck had a code for cyclinder 2 misfire came on and was fixed and light went off for 2 weeks but after that the light comes back on and check it again and the same code came on and fix it again. The light went off and came back on again then went to the dodge dealership they did a diagnostic and everything was working great and they restarted the computer and then a week later the light came back on and then turns off and turns on. WHAT IS WRONG