With the information provided there is no accurate way to tell. Is your truck stock? no chip tuner etc?. Do you have the ability to clear and/or read the code?, is your engine oil level ok?. Have the injectors ever been replaced under warranty?.
Cheapest thing to do would be to put ona new fuel filter if you havent done so already. If that does not work then it could be many different things. Injectors, high presssure pump (cp3), fuel rail relief valve, could be a high pressure leak. If your chipped you may be running out of good fuel supply to the cp3, you may need a fass or airdog lift pump (duramax's dont have a lift pump from the factory either btw.)
Keep in mind without more detailed info it is impossible to be certain what is going on. If you get me more info i can give you a better idea hopefully.
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