pablo help

now when i drive truck oil pressure goes between 60-62
and i do not have power like before
what is your take on this
thanks

 

It is 0.4-05 g/h
And I have exhaust leak same where by egrs or turbo but I can nut find and when I use exhaust brake I can hear there is leak
Did you have anything like that before or can all that power lost be connected to that
I know some times I can hear wistle on highway
Could be turbo I don't know what is turbo pressure because I do not have gauge for turbo boost

 

there was exhaust leak replaced manifold
but still have that when goes from 1speed to 2speed to 3rd, rpms goes to 20 with fan on and shifts bad
but when is fan off shifts perfect and
could be camshaft sensor or crankshaft sensor
what would be your take on that
thanks