Ok, check engine light came on, turned the car off, restarted, it ran rough, then died. Restarted again, ran even rougher, then died. Restarted, it started up, and ran fine. Check engine light was still on.

Pulled a code 41, which is cam signal lost or interuppted.
Another problem for code 41 is cylinder select error - MEM-CAL or ECM problem. Whats that supposed to mean.

I put a spare sensor in, no difference, but car still starts and runs. Unplugged ECM, no difference..

I am guessing the camshaft magnet is out of alignment, or requiring replacement.

Is there another easy way to replace it, or is my timing chain cover gonna have to come off? I have no problem with any repair, but its just something inconvient.

Also, if that magnet DOES fly off, the car will still continue to run, just that if I attempt to restart it, it won't start, right?

Also, if the magnet flys off, is it gonna end up in the pan, or will it still require removal?

Any tips, suggestions, or advice is really appreciated.
Thanks in advance.

http://www.padgett.ws/cars/cammag.htm

I pulled the sensor, and looked at where the magnet was supposed to be. Its gone. the plastic retainer is still there. The car still runs...

I am getting a new one from gm, and I wonder how it can even fly out in the first place?? Is the front retainer weak?

The timing cover will come off. With 135,000 kims on the engine, might as well change the chain if it needs to be done. Besides, I wanna do it right.