Hello, I have a 2003 Nissan 350z A/t with 267k miles on it and the check engine like pop up with code P0507. The car it running fine but the light will pop up for a couple of days then go away for a couple of days then it will show up and so on. I kind of cleaned the throttle body and when I say kind of was i just lifted the butterfly and cleaned it around because i didn't want to take it apart and have it reprogrammed. That didn't help.  I checked for leaks and didn't hear or see anything. I took it to a shop and they told me it was the crank shaft sensor. I didn't take their word for it only because they tried to sell me other stuff i didn't need. any help would be greatly appreciated.