P0336 after Opti swap

[alone_and_insane]

So I've found a lot of threads asking about this, but not really anything that can give me definitive answers, so I thought I'd try here.

I recently did an opti swap on my car. I installed a reman AC Delco unit I got from RockAuto. It fixed the high rpm misfire issues I was having before, but now I've had a couple instances where I get a P0336 Crankshaft Position Sensor range/performance code when I start the car. Last time it happened, I cleared it right away, and it didn't come back the rest of the drive.

So I have a couple of questions:

1. What is the failure mode when a P0336 is set? I've seen conflicting reports as to whether or not it has any drivability impact or if it's just a dummy code that doesn't really do anything.
2. What is it about the opti swap that could cause this code to set now, when it didn't before?
3. Is it possible that when the car was tuned, they tuned it to the characteristics of the faulty old optispark, and it just needs to be re-cal'd with the new part?

[JoeliusZ28]

That means that the PCM is occasionally seeing conflicting readouts from the cam and crank sensors.

Could be any of:
One or both of the sensors are faulty (so possibly the opti again)
faulty wiring
slop in the timing chain or (or maybe cam degreed incorrectly?)



Definitely a tricky one... I would doubt the tune has much to do with it but i could be wrong. Is that the only code its throwing? Personally I'd see if it gets worse over time if it isn't affecting the drivability of it.

[alone_and_insane]

Yeah, that's the only code. I doubt it's faulty wiring or the timing chain, because it never once threw that code with the old opti. Could it have been installed incorrectly? I didn't really pay attention to how the old opti was aligned when I removed it (didn't do any paint marks or anything like that), but it sure seemed like it was made to only go on one way...so that's the way we put the new one on.