the crank sensor on these engines is only there to feed the OBD-ii misfire detection requirement. it compares the cam and crank angles i suppose and if they're too far off it figures there's a misfire.

you can imagine how the cam to crank relationship looks with a really lumpy cam. it causes the timing chain to jog back and forth a lot and cause the same kind of result as a real misfire.

the check engine light flashes if that happens. that might be a good clue, if you can find a routine that looks like it's flashing the CEL rather than just sticking it on, you could probably track that back and find the memory containing the error bit, then go back from there and find the misfire detection code.

it'd be nice to find the parameters so you could widen the angle that it considers a misfire and still retain some misfire detection, but other tools don't have that so people tend to just disable the error code so their dash doesn't blink at them. also the misfire detection doesn't SEEM to do anything other than flash the light, but nobody is 100% sure about that