So I recently pulled my old LQ4 and put in a new one now Im throwing P0342 which is a cam positioning sensor low voltage code. The things that have changed, cam, I went from 226/234 .598 .612 to 234/242 .605 .615, ls6 crank, and longer connecting rods(6.3). It starts up fine, runs fine, doesn't seem to loose power at all but when i reach 3200rpm the tach drops to zero then throws the code. I can rev it fast from idle and it will work fine, when I rev it slow it drops to zero every time and after a few seconds the tach starts working again. Here is what ive gone through so far. Replaced cam sensor, crank sensor, battery, pcm, checked the wiring harness from the pcm to the cam sensor then made a new harness to replace it and still nothing. I also checked the cam bolts and grounds and everything is fine there. I haven't tried a crank relearn yet, but that's next on the list. Could this be something that can be corrected in the tune? Would the bigger cam, ls6 crank or longer rods effect this? Any help would be greatly appreciated this is starting to drive me crazy!

 

Crank relearn was the first thing that came to mind.

 

Thanks for the tip Patrick I'll try it next.