2000 Ford 7.3L Power Stroke: PO272/PO278/PO284/PO308 Codes and Injector Failure Diagnosis

The issue began with the 'water in fuel' warning light illuminating. I drained the fuel separator and replaced the filter, but the engine continued to run roughly. After attempting a full tank drain without removing it, I refilled with fresh diesel—no improvement. I took my 2000 Ford 7.3L Power Stroke to a dealership, where they retrieved codes PO272, PO278, PO284, and PO308. They attributed the issue to a dirty fuel system, stating 'most likely from the tank.' They recommended replacing the entire fuel system. I opted instead for just dropping and cleaning the fuel tank, but the rough running persisted. Unsatisfied with the dealership's diagnosis, I brought the vehicle to a non-Ford diesel mechanic. He retrieved nearly identical codes: PO274, PO272, PO278, and PO284. He identified three faulty injectors—#4, #6, and #8—and recommended replacing all four left-side injectors along with the UVC wiring. After the repair, retesting revealed a new fault on injector #5 (PO275). I spent $1500 on the left bank and have since concluded that the vehicle now runs at least 98% better. I’ve decided to defer fixing the right-side injectors until I can assess the full cost and potential long-term reliability. This experience has raised serious concerns about Ford dealership troubleshooting methods. Instead of identifying actual injector failure, they blamed fuel contamination. My mechanic’s diagnosis was more accurate and actionable. What are your experiences with 7.3L Power Stroke code PO27x issues? Did you find similar injector-related failures or fuel system problems?