Thursday I got a CEL and did not check it until today, P0191 - rail pressure sensor range performance. According to the Freeze Frame the truck was idiling at the and it was at full temperature. I cleared it and I will see if it will come back. Any suggestions?. My dealer is booked for 2 weeks and my truck is needed 24/7. The truck is the 4500. Maybe a FCA??

 

The Best Thing To Do Is Get Into Ur Dealer. There Is Proably A Flash For The Pcm To Take Care Of This.

 

this is resolved by a flash. It will do no harm to drive it for a little while before you can take it in

 

The light has not returned, the dealer will laugh at me if it didn't have a CEL on.

 

What dealer? the CEL has to be "on" not stored in memory?

 

ok, i take it back. I just saw that it was a '08 4500. There is a good chance it is a fuel rail pressure sensor. Other than that it could be a leaking injector. I would ignore it until the code returns. Could be just a fluke thing