peterbilt 387 with ISX engine shuts down on adn off

[alborz]

Long story short : my 2010 peterbilt 387 with cummins isx died on me on the road . towed to cummins shop. they charge me $450 and gave me a list of codes with 2 active codes.

code 255 fuel shutdown circuit and 2637 DOC face plugged.
and blow by #6 exhaust leak.

Anyway I disconnected the exhaust right before the DOC and headed home. On the way home at fuel bay stopped for 10 min and truck died again. any attempt to restart the truck was unsuccessful. about 5-6 hrs latter I could start the truck and drove home for another 130 miles. Since then I clean DPF, DOC, check wiring, check turbo, replaced coolant filter and coolant level sensor. I attempted to start the truck but no success. I took off the cup from fuel shut down solenoid and started the truck. engine warmed up with yellow engine light on. could not retrieve flash code. I drove it today for about 20 miles. everything seemed OK first but,
It died after few minutes of idling.
when it dies, it doesn't restart right away.
when it dies red and yellow engine lights flash several times.
truck can be restarted 10-15 minutes later but it dies after a few minutes.
when restart accelerator pedal seems not working for first several minutes.
I took off the engine breather filter to see if it makes any changes but engine died like before.

Please help me what should i do since I'm about to broke and loose my everything.