Stop engine light quandary?

[Bmyetrkg24]

I got a 2009 Pete 386 with the infamous 871 money trap and had a recent problem with to many quick and abbreviated regens so of course I started with a egr tune up and cleaned the egr, egr piping venturi and venturi tubes cleaned imap and all the other sensors installed new doser inj the old one was clogged pretty bad I removed the exhaust pipe from the front of the doc and noticed the screen was mostly plugged only had a small area where any action had been taking place so I blew all that out with shop air and thought that was my problem so out it all back together and fired her up she purred like a kitten no check engine lights and since I don't have insite I idled a few until it needed a regen so I started one and 17 minutes into the stop engine light went off and shut the cycle down I shut the truck off and it went away I drove to mechanics no lights my mechanic buddy has been saying turbo but it seems like more of a regen issue to me? Prior to this I had numerous crankcase pressure lights which makes me think turbo a little so I'm needing some help guys! She has a new egr cooler new egr new air compressor new delta p new imap many new other parts and pieces but maybe this is enough info to get us started she has 750000 miles