Just for clarification, because you’re in a different circumstance, my cam issue on the e60 was a no fault code issue where I addressed everything ignition related. Finally it failed once, reduced power warning, said cam position invalid which prompted replacement of cam/crank sensors. Took 6 months of irregular driving for it to appear with intermittent stalls the whole time. Runs more peppy now too. N54 vs M54 though, others might have more ideas.