ISX CM2350 fault code 4727

[victory26]

Hello everybody, I have a 2014 Volvo VNL with a ISX CM2350[demandated by top forum member here] that's throwing the fault code 4727 . This issue it's been going one since February of this year. It comes and go, when CEL is on the truck has almost no power and the engine it's running different, it idles more rough and it's kind of hammering when you step on the accelerator when driving. I have tried everything quickserve suggests but the problem didn't go away. I have replaced the check valve that's in the back of the head on the fuel return line and that didn't help it. I've also replaced the fuel rail pressure sensor, the fuel pump actuator and the pressure relief valve. It passes the fuel rail leak test no problem. If anyone has dealt with it before , please share what you have done to fix it! TIA