I have a 07 cobalt, 2.2 engine. About a week ago the check engine light came on. Hooked up a scanner and the codes recieved were P0340 and P0341, which are related to the cam sensor. I went into my local auto zone to buy the sensor, the sales guy told me the car requires two, but he could only find one on the diagram. I bought the two, replaced one thats beneath the oil cap, but I cant find the other. Does anyone know where it is, or if the car even requieres two?