Cam sensors

[prschmn]

I am wondering if anyone or how common it might be to have a cam position
sensor give incorrect values. I have a 996 with PIWIS telling me the cams are both way of of spec but have measured and they are absolutely in spec.

[JFP in PA]

The PIWIS system measures two cam position values: cam position and cam deviation. The reason for this is twofold: (1) Cam drives all have some degree of slack in them, and (2) the engine has VarioCam, which changes the cam timing (read position) relative to the crank position for optimum power and emissions purposes. Because of this, when the engine is running, the cams are nearly always somewhat off ideal installation position, and Porsche sets this deviation range at +/- 6 degrees. If the cam(s) exceed this value range, most likely one or more components have worn a bit, allowing the cam to move more than it should, and this is a common issue, particularly on the five chain version of the engine. Fortunately, the fix is to replace the worn chain guide and the engine goes back to being normal.

[prschmn]

Thank you for the answer but I think I need to rephrase the question. This is in a GT3. I am seeing clearly wrong values I.E. 0 deviation at 2000rpm but 20. At idle.
Actual angles are also clearly wrong.
So I am thinking somehow the sensors are mistriggering.