check engine lite= knock sensor

[suville]

as the title indicates my check engine lite came on, scanner says knock sensors ok replaced them... within a few miles engine lite again scanner says knock sensors ok well we didnt replace the wire harness first time so replaced wire harness within a few miles engine lite again mechanic say "it a runability issue" ???? ok replaced spark plugs noticed a slight difference in response yup within a few miles engine lite again. WTF Im thinking I could have a knock sensor that is defective but ??? At 95 bucks an hour for shop rate this is getting expensive and Im getting pissed ! Anyone ever experienced this situation and have any recommendations?? Im at a loss as to what the hell is going on with this confusor crap any advise or recommendation would be most appreciated. Thanks