Help with Hino

I have a 2014? 195 down as we speak. That is a four banger. It has a hole in the rear piston about the size of a pencil. Is that number 1 or 4? The hole is similar to the angle an injector sprays. Injector shop says all flow about the same and the spray patterns look good. They can not get any information on required pressures or flow. Hino and the fuel system manufacture have that all locked down. In fact they cannot buy injectors anywhere other than Hino. There are about $1000.00 each. I had previously ordered parts for an inframe which cost about $5,000.00. The turbo looks OK but had oil standing in it. The intake manifold is an oily smutty mess how ever the exhaust looked good, dry. How is that possible? How has this impacted the emissions system and what would a DPF cost. Can it be saved?
Not familiar with the explorer 3.0. Have been highly considering a Diesel Laptops on and off road unit. It is supposed to have coverage on these and do regens.
Maybe we need to do a little better job of knowing when to " Just Say No " if you are buying or working on them.
Looking for replies with you. All appreciated.

 

Not sure about a Hino layout but a couple of things stand out like the turbo with standing oil in it, I have replaced a few turbos with oil seal leaks and that could certainly account for the intake mess, on the other hand an egr cooler that has been leaking awhile makes a big intake mess also if it was never addressed, its hard to tell the difference between oil and fine soot/coolant mixture at first glance without further inspection/testing. DPF's are labor intensive, it's easier to swap yours for a reman and be done with it as to always be guessing whether or not you cleaned it good enough without having it baked also (consensus is all over the board on this). The hole in the piston is not an option. I ALWAYS press to have the head sent to the machine shop for valves/seats and pressure testing, not much help but something to think about if you want to bring that unit back from the dead...