Injector spill valve and pressure leak

[Rounded_nut]

2014 cm2350, I had a fuel leakage code, found number 2 fuel supply line out of torque spec, tightened and cleaned up the fuel residue. I ran the leak down test and dropped to zero in seconds so I replaced the fuel pressure relief valve, pressure still drops off to zero but takes a smidgen longer. Now a new code has popped up for the injector spill valve, and intermittently for high fuel leakage. Before I spring for a new injector and supply tube, is this a reliable code or does it more frequently point to something else?