Recently I notice my car losing accelaration power after looking found out it was probably a bad injector, replaced it and the accelaration did pick up for a few days still runs better but now requires to pump the gas pedal to start and shakes slightly, gas mileage has suffered and a smell of exhaust seems to.be coming from under the hood accelaration power is slowing too is it possible we missed a hose when reconnecting everything or something else any help would be greatly appreciated. Thanks!!