I need help

[Dmaxkid]

I have a 09 duramax with a black max tuner and fuel rail plug a Fass pump 95 gph and pulling a hill with my trailer it tripes a code for low fuel rail pressure. I am lost at the Fass I have 9 psi of preassure and they say that it should be from 8-10 psi so I know that is good I have no clue what else to look at. Any help please
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[Gmclbz]

Rail plug leaking?

 

[Dmaxkid]

No not at all
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[Atouchofgrass]

Do you have a race valve? Have you done a bottle test? If you don't know what that is, search it. You may need to shim the rail plug if you're getting a low rail pressure.

 

[Dmaxkid]

How do you shim a plug there is no relief on it like the stock one
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[Dmaxkid]

Could it be the cp3
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