Working principle of diesel engine muffler:   
    The main principle of diesel engine muffler is to use porous sound absorbing material to reduce noise.  The sound-absorbing material is fixed on the inner wall of the airflow channel or arranged in a certain way in the pipeline, which constitutes a resistive muffler.  When the sound wave enters the resistive muffler, part of the sound energy is converted into heat energy dissipation by friction in the pores of porous materials, so that the sound wave through the muffler is weakened  
Resistive silencer is like electrical pure resistance circuit, sound absorbing material is similar to resistance.  Therefore, people call this kind of muffler resistive muffler.  Resistive muffler on the high frequency muffler effect, the low frequency muffler effect is poor.

    1, Removing the muffler has little effect on the engine, just a tail section.  

2, fuel consumption will certainly increase, even if the back pressure muffler drum is slightly increased fuel consumption, not to mention direct

  3, The sound is not clear and I haven’t heard it before. It may be the sound of the engine, welding leakage, and the exhaust gas flow caused by chaos without muffler muffling.