09 Cascadia dd15 no egr no dpf loses power

Hey guys new here Don’t know where to start from 09 Cascadia dd15 egr and dpf is deleted. It was doing all good butt since few days it’s giving a hard time. Loses power when accelerating hard and check engine comes on after few seconds of acceleration and power comes back As soon as the check engine goes off it loses power again It does the same on bobtail too Any advice plz Thnx

 

Thnx for replying there was a code 1077 fmi 7 and the dealer checked it they said it’s the pressure limiting valve they replaced it charged 800$ and still not fixed

 

Thnx I checked all the fuses didn’t find anything will take back dealer I guess. There was a code 1077 fmi7 dealer said it’s the pressure limiting valve they replaced it still not fixed

 

fixed it was the fuel filter full of metal shavings not sure where it’s coming from. Butt I did change the fuel pump few weeks ago

 

Not sure if mechanic did all that I was told for the filter only Have to see him tomorrow for the bills. Will make sure. Thnx a lot And do u knw wht can be the cause metal shavings? Thnx