P3040 Code and Rough Idle

[HMYGTI]

Hopefully someone can help with this, A few days ago my MK5 GTI developed a rough idle however it still drives fine and on cold start it idles at its higher revs fine but when it settles and drops the idle is incredibly rough. I checked for any fault codes and got the P3040 code for the crank position sensor. I was just curious to if anybody else has ever had this issue as i would have thought if it was showing this code it would cause more of an issue than just a rough idle.

Thanks

[FJB]

I was getting an intermittent bad idle and would get a crank position sensor code, the code would clear and idle normally, but would return. A put a new crank position sensor in, which cured the problem. I noticed that there was some crud on the tip of the old sensor once I had removed it, as I already had the new one I installed it, but it may be worth you removing and cleaning yours before buying a new one.