Question on smoke output

[joed2323]

Cm2250, 2012,
Truck has repeated frequent Regen issues, been on going for awhile

So looking at the codes,
first thing I did was remove the lower exhaust pipe below the doc, and the intercooler intake pipe from turbo fired truck up at a idle, and nothing but a oily/wet smoke shot out the exhaust piping/doc, it smoked up the whole garage.... I could wipe my fingers in the oily crap it spit out, or puked out warming up...

I didn't smell any diesel fuel, it didn't burn the eyes, but lots of black smoke shot out the exhaust pipe.

5 mins or so I bolted the piping back together and ran a few tests.

First one was, the fuel pressure test. The truck failed it miserably, it dropped like a rock from 29,989 to easily under 20,000 in like 15secs... Numerous times.

Did the one cyl cutout test, and all injectors sounded decent, motor didn't die out.

I replaced the fuel rail check valve. And it held fuel pressure after replacing the check valve.

My question is, once the motor warmed up, that black smoke quit blowing out the exhaust, but at a snap of throttle it still blew black smoke out (not as bad) where could all that black smoke be coming from??? Obviously this is contributing to all the excessive frequent regen codes..

The turbo is orginal, but the turbine wheel has play, im thinking it could be coming from the turbo or leaky valve guide seals, once motor warms up it doesnt piss oil out? Oil consumption isnt overly obsessive

Once the motor warmed up it quit smoking like a whor@
But have has repeated issues with this truck, I assumed at first it was a injector issue and over fueling or dumpin fuel but I had the exhaust pipe back off after the motor warmed up and it seemed like she quit pissin black smoke/wet moisture

Literally when I first fired up the truck with that bottom doc exhaust pipe off, It spit out a huge gulp black sooty oil/watery mixture... I had my head near it and it did not burn my eyes so my assumption of over fueling was wrong at first with the drop of fuel rail pressure at start...

Replaced that check valve and it fixed the drop of fuel rail pressure. It still doesnt explain the "high smoke output"