I've recently did ported heads and cams and have got the same code ever since. My car runs fine though besides the cel with p0340 code. I replaced alt, cam sensor crank sensor. Still getting code, guessing either I need another harness or a pcm. ****ty deal...let me know how yours works out for you and as soon as mines taken care of I'll let you know what was causing mine. Good luck this codes a nightmare.
This is why we play the game... to separate the contenders from the pretenders!