Engine management light

[Pez]

Engine management light came on the other day, took it for a diagnostic and the code was "Crankshaft sensor P1347 bank 2". Got the codes cleared but it came back on last week, then went off by itself then came back on a few days later then went off and came back on again 
Anyone know what this could be on a V6? I'm thinking timing chain stretch or something but would it cause the light to come on and off like that? There is some slight timing chain noise but it's been doing that for a while and doesn't seem to have got any worse. I was thinking of doing an engine flush as a read somewhere that the tensioner can get blocked with sh1t. Heres the video of the noise, any help would be great cheers.

http://www.youtube.com/watch?v=A3J5AczIVv8&feature=youtu.be

[navmk4gti]

Could just be the sensor or the engine speed sensor bud.. doesnt mean chain is out.. but course be on safe side get chain checked mine does sound rattly too when engine is cold.. once warm its very quiet tho.

[Pez]

Could just be the sensor or the engine speed sensor bud.. doesnt mean chain is out.. but course be on safe side get chain checked mine does sound rattly too when engine is cold.. once warm its very quiet tho.

Is it simple enough to check the chains using a timing gun? I'll swap the sensor out over the weekend and see if that does the trick, fingers crossed it's just the sensor on its way out.