Hi my 2006 saab 93 was playing up it went in to limp mode so i got a new refurbished ecu the saab place said he couldnt get the data off my old one so i had to take the car to them , picked car up got half way home the engine light come back on so drove it home as it drove normal tried it again it had loss of power but dont think it was in limp mode this time i checked it with my cheap scan tool it comes up knock sensor 1 circuit bank 1 or single , i rang the place where i got ecu from he told me to send ecu back which i did i fitted second one yesterday 20 min engine light came back on checked with my code reader it says the same thing knock sensor 1 circuit bank 1 or single. any suggestions where to look thank you someone said ecu isnt programmed properly, then i read could be CDM what ever that is. thank you