got a 91336 code.....?

[Motorboy8769]

i got a p1336 crank sensor code today and drove the truck home no issues with the check engine light on i parked it cleared it and started it and drove it again and no code this still scares me a bit what would cause this code to happen once i have herd broken rockers and cam lobes but i am sure my truck wouldnt sound normal my oil level is good not too high and i dont see any fluid in the tail pipe......