Back pressure: It is a form of resistance to the free flow of exhaust from the cylinder head. It may be due to badly designed or fabricated or choked exhaust manifold, catalytic converter and/or muffler. Related posts: Personnel Management Operative Functions Administrative Role of PM Competency HR Management Role Change Personnel Policies Personnel Procedures Appealed Policies Implied Policies Specific Policies Personnel records Research Pure research Personnel research Attitude or Opinion Survey Turnover Secondary research Applied research Personnel audit Read more articles Previous PostBackfire Next PostBattery capacity