Truck has been needing turbo work for over a year so I finally did something about it. We started with full diagnostics including injector exam.
EGR cooler had very small leak which had allowed some rust build up inside turbo creating sluggish operation and overboost, insides had no pitting so they anti siezed and reassembled.
Oil/water delta was 13 degrees so replaced oil cooler with newer OEM also replaced cracked EGR cooler with Bullet Proof cooler. Replaced oil screen with new steel (old one not torn). Replaced stand pipe.
Injector test showed a nice flat graph.
Truck is running like new again with quick spool up and boost holds right at 24lbs in stock tune.