what damage does driving with out an exhaust

on a 2t weith no pipe on the so called reflective phase there is no wave to push air back into the exhaust.. there is however a vacum inside the cylinder that draws new fuel in, with no pipe the draw on air from the exhaust port is more coefficent so the mix isnt mix, its unfueld air comming in the exhaust port.

put basicly removing the pipe will cause a lean mixture with fuck all power, dead engine,