bought a 2017 kw w900l

[Waterloo]

Knock off reader is fine, it should do all you need to do.

Rebuild the fuel pump, they still grenade.

EGR Tuneup, Intake Manifold Pressure Sensor, Exhaust Back Pressure Sensor, Crankcase Breather Element, you need to inspect, and if the old filter element filter is installed, purchase the new install and forget maintenance free filter cartridge.

SCR Doser, it is under the floorboard near shifter, inspect for leaks. Service SCR system. There may be a spin on urea filter in there somewhere too, change that out.

Exhaust fuel doser, I would replace if the paint on it has not been disturbed. Unless you plan on fixing the issue, then don't worry about it. If you go to Canada, some Eastern states and or California, you may want to keep the system intact.

Run the overhead. Inspect cam and rollers.

Bake and de-ash cans.

If keeping emissions, install the Amsoil remote filter system to clean the soot out of the oil.

Swap the gears in the rear end... That is just off the top of my head.