KHD

Sorry for the length,its been awhile but having problems with van. out west this year going up grade in NM with cruise on about 65mph, it automaticlly dropped down a gear stepped on gas to keep speed and no power. Pedal all the way to floor, nothing. put in neutral then engine quit. Tried to restart would but then stall again. Finally after a few tries started no problems or check enging light. Continued on to AZ, NV, then in UT same thing, going up these steep grades lost power again. Pullover and tried to restart idled rough stepped on gas sounded like no fuel and misfired then check engine light. after about 15 min got it started again, OK for a few miles, then same thing. Got it started again everything OK except Check engine light on. Outside temp then was 114. Next day in CO. same thing, only on the steep grades. Anyway its the 4th weekend can't get looked at. Got to NE no problems, took to GM dealer Pulled CODES P0151,131,171,174,300. Then checked all systems, and were OK. He suggested it may have been bad gas, to much ethanol, or possibaly a bad fuel pump. didn't have one in stock, so i saved $800+. got home no problems (upstate NY), and no problems since, till today, throw a P0430 code. I know what the codes are, I have a OBD 2 Scan tool, but the fix is puzzling. Have been told gas, fuel pump, intake gaskets,O2, Cats. would like some feedback.