The Malfunction Indicator Light came on in my truck yesterday and I cant figure it out, the truck still runs great but no longer smokes. (Not that it did that much in the first place.) I happened right after I put my quad fooler back on. Right now I'm running crazy larry my power puck and the fooler. If I had trouble with my rail pressure valve would this set the light off? Where should I start checking?

And the bully dog showed no DTC's

 

No my prv showed no codes, if you have aftermarket inj or a fuel pump with filters. I would recommend a rail cap for like $60 if you think that is the problem. John at Floor It can help.

If I remember right there is a way to check it first though. Try to do a prv search. WOP helped me check mine. I think you take the bolt out of the top and dry it out with a rag and start the truck and shut it back off. if there is any fuel in it at all its bad. I wouldnt recommend a cap though without 2mic, clean fuel or aftermarket inj though.

Did you try the on/off/on/off trick to read the codes? Your sig is incomplete or you dont have enough supporting mods to be running crazy larry and a puck stack.