What is this sensor?

[boylin]

With the yellow plug, its round and doesn't really have anything on the back of it.

http://i72.photobucket.com/albums/i200/boylin/boylin032/IMG_2739_zps3cef4062.jpg (http://s72.photobucket.com/user/boylin/media/boylin032/IMG_2739_zps3cef4062.jpg.html)

http://i72.photobucket.com/albums/i200/boylin/boylin032/IMG_2739_zpsd22ff5bc.jpg (http://s72.photobucket.com/user/boylin/media/boylin032/IMG_2739_zpsd22ff5bc.jpg.html)

[Cam]

Knock sensor

[boylin]

thank you

[saxo_turbo_azy]

Did u find problem