ISX15 CM2250

[JDMagnum]

Long time reader. First time poster:
Story time.
Customer asked me to look at ISX15 CM2250 for him.
He bought it from southeast somewhere not too long ago, only got about 1500 miles on it before having serious drivability issues with it. Truck was demandated by seller prior to buying the truck.
I mainly do John Deere/ Cat equipment, but am proficient in engines diagnostics/repairs. But took on the work. I am second person to work on this.

The truck had VGT code 2387, Fuel code 0559. Was immediately concerned with 0559 code.
And also truck needs cam/rocker replaced, #5 exhaust lobe is worn.
Previous shop replaced injector 1 and 3 with cummins oem injectors.

1. So far, I removed fuel pump head and inspected it, has original ceramic plungers, they were in good shape, what a relief that was to see :), after reading all the horror stories online. Installed updated OEM fuel pump head (steel plungers) and tapper/followers.

2. Engine starts and runs. #5 has slight knock that goes away when cylinder is cutout.

3. Solo cylinder cutout test: Engine will run on each cylinder by itself with no significant difference noticed between the 6.

4. Rail pressure hold test: Rail will drop to zero has soon as key is shut off.

5. I removed return line off rail relief, capped the line, left rail relief open, started truck, relief drips constantly, worse when rail pressure is higher. New relief is ordered but do not have yet.

6. I very much question the demandate and shoddy exhaust work on this thing so wanted to pull ECM data. I have Insite 8.7, and Calterm 5.3, I'm familiar with Insite from my years working at Case Dealer. I have zero experience with Calterm and wasn't able to pull the ECM data to get it checked out.
If someone could help me with that part that would be great.

So that brings us up to date. Plan from here is.
Get ECM data pulled and forwarded to get checked out.
Get new relief installed.
Get fuel system tests - passed.
Once confident the fuel system is up to snuff will go on to replacing camshaft and rollers.
After that checking Turbo actuator for play/wear.
Checking exhaust was done properly for demandate.
Plan on doing 6 dime mod, and maintenance free breather filter

If there is anything i'm missing in my diagnostics steps or plans let me know.
Mainly looking for help right now to get data pulled from the ECM.

Thank You, What an awesome community and wealth of information you all have been!