09 prostar horrible Mpg

[earnies2]

Terminator? Broke a piece off an exhaust valve and it went out the exhaust and nailed the turbo.
The shop that did the work was a machine shop they said the casting was good so we rebuilt it I found out after it was done that everyone says replace with new so far it's been good.
I run mid west to east and mostly light....13 spd 355 rears not in a hurry easy on the pedal...