i didn't wash the engine. but i think that it just happened to be wen i washed my car i just happened to have this problem at the same time. so i'm thinkin i might have a clog in the line or a bad injector. the car bucks really bad. now it only goes up to about 2600 rpms. and i also over heated at a point and need to put water in the radiator. so i have no fuckin clue what it could exactly be. but i guess i'll just have to start trying things.