Originally Posted by Smokerll
If it was me, I'd put the old gear back on. Whats a smidge? If the timing marks were lined up on first inspection then I would think things in that area are ok, and who knows what that new gear fits. If it was off just a smidge, if its a small smidge I doubt that it would cause it to run that rough. While your in there you could put a new chain on. You didn't say anything about checking injectors or spark plugs. My guess is you will find a dead cylinder or two.
You have to go back to the top of the post. The car has new wires and plugs are two years old. A dead plug or injector would not set the CODE 18 error.
The new gear is the right one for the car. However, who knows what quality control is like these days. I replace the motor mount on the drivers side at the front of the car last year and the replacement was a piece of crap that I had to re-machine to get to fit and it was a $47.00 part; it was made in China. The gear set came from Advance Auto.
I think I will put the old cam gear on and the old crank gear on and see how they align up. It is possible that things moved a bit on me. If the old gears timing dots line up and the new don't, then I will know it is a machine error.
A smidge is like maybe a 1/16"? or maybe less. The teeth on the two gears have to be in align or the key-ways will be off enough to prevent sliding on and I think that is what I am seeing, just enough off that the gear won't slide onto the key on the shaft. If it is only off that much, then moving the crank shouldn't be of any concern is what I am thinking.