Got, in my truck this morning to go to work, and a trouble code p0191 pop up on my programer. It stated it was the fuel rail pressure performance. Truck started fine, ran fine. Still getting 20.5 mpg. What do you guys think?

2006 mega cab 5.9lt with 37k on it. edge attidude with juice. air intake

 

Had it recently on my stock 2006. Took to stealer and they flashed it. Done deal.