I tried everything I could but nothing... But here's the thing... My check engine light is not actually on right now, it comes and goes ever since I got the truck. I figured it would have trouble codes stored in the computer. Does it do anything at all if the CEL isn't currently on? I kinda hope it comes back on soon, I am curious as hell to see if this works, and I've been wanting to know why its coming on in the first place.