I was driving home from my friends wedding yesterday when i went to pass a semi and got 2011 6.7 up to go around it threw the low fuel pressure light. I was in the middle of nowhere so i decided to go as far as she would make it before breaking down (she never did). If i was just cruising along at around 70-75 i didnt get any lights or warnings. But, as soon as i would get after it to pass somebody that low fuel pressure light would get thrown. It seemed to me that if i just crept it up to get up to passing speed it wouldnt get thrown, but if i mashed on it then it lit up everytime. The truck didnt sputter or anything, if it wasnt for the chime i wouldnt have even noticed it.

 

fuel filter.... ?

 

It's pretty much a new filter i just got it 3 weeks ago if that

 

Sounds like you need yet another fuel filter. A bad tank of fuel can plug up the filter quick.

Think about it for a minute...when you're cruising with a steady throttle your truck isn't consuming much fuel. When you hit the throttle the injectors spray more fuel into the cylinders, so the HPFP has to push more fuel to the injectors, and you end up pulling more fuel through the filters. They may flow enough fuel to maintain pressure at low throttle levels, but ask for more and the system can't deliver it fast enough.

I'd replace the filters and go from there.