I have two issues with my truck and unsure what they are. Both just started today. 1. I am having a raddle sound coming from I believe up front. Unsure sure where. The faster I go the little louder but not much. I stop and rev the truck up No sound. So it only happens in motion. (VISUAL truck looks fine under neath. With out help unsure of how to check and how to check. 2. Check engine light is on. Unsure why, otherwise it would be fixed:doh:. But anyways the only changes in last two days have been i filled with diesel. I made sure I put right fuel in. Plus I put on only about 5-20 miles since then. Second I installed backup camera today, unsure if I hit a sensor or disconnect cable. I connected the wire needed for the backup live feed into fuse box. Unsure which one I used(my stupid) but unsure if voltage change would of done it. Any ideas for the two?