i get code 11 (cam sensor) fault on my car which causes it not to start sometimes. (wait 5 minutes and it'll start beautifully)

i replaced it with a 2nd hand item off a known good car with no starting issues, is there anything else that could cause fault 11 or should i just buy a new cam sensor?

Cheers

 

ok it appears i am a complete and utter idiot!!!
Just had a check over the codes again and number 11 is the crankshaft sensor!! can't believe i misread it and replaced the cam shaft sensor. oh well first light tomorrow and i'll get it changed. Phew thought i was going mad there.

classic schoolboy mode disengaged..........