Hi there i have a 1990 Toyota Celica, whilst working in engine, i accidentally hit what i believe to be a sensor in the engine, and it snapped in half. i don't know if this is a sensor, or what it does or how to replace it please help me. here is a picture of a similar engine, with the thing i snapped of circled.

its a green colored thing its in a line of 3 similar looking things, its located the right of the head of the engine. please help!

here is picture http://img543.imageshack.us/img543/913/brokensensor.jpg

10pts best answer!