After doing a head gasket replacement on my 2012 Prius, I started the car and my engine is knocking pretty bad and im getting engine misfire codes and the P0441 code. I've cleaned the EGR components, I've checked my purge selanoid valve, MAP and MAF sensors, checked my hoses and wiring. None of my pistons were bent. I followed a Toyota manual the whole way through the repair. Maybe my crankshaft is trashed? Does anyone have any ideas?