camshaft,How many camshaft sensors are there in my 2003 infiniti m45? 2003 Inifiniti M45

I changed all the spark plugs and my car is still running like shit. I tool it somewhere and they said change the camsha position sensor. Now idk if it's 2 or one. Cause I know the crankshaft sensor is one or two but u can't remember

My car has 163811 miles.
My car has an automatic transmission.