Dumbfounded

Hello hope y'all are having a great weekend.

My problem........
2008 Peterbilt 386. 1.200000 miles. Cat C-15 deleted and PDI tune. So anyways, driving along just fine and my motor will cut out for a split second. This happens intermittently for the past 4 days. Til finally whatever is loose or bad makes my truck lose power. boost goes to 0 , oil pressure gauge goes to zero . Still have oil pressure just no gauge and no boost. Limp it to a shop pull up the codes and it's showing oil pressure sensor bad , air ratio sensor bad and boost pressure sensor bad. Cleared codes but they kept coming back. I was out of town so I limped her back home and took it to my mechanic. He checked all the wire connectors to all the sensors and ECM and found them all good. Cleaned battery connections also . Problem got a little better and went back to intermittent . Two days later problem came back full force . Motor runs fine just no boost or oil pressure , on the gauge. Idles smooth , revs up nice and clean no smoke .
First mechanic thought all 3 sensors had the same ground wire and it was a connection problem. My mechanic said all wiring was fine you have an ECM problem . Anyone deal with this before and could help me out would be greatly appreciated.

Thank you.
Eric Algiers
Algiers Transport INC.