So basically Im in the middle of swapping in a complete 50k mile vq into the Z. I bought the 3 sensors that are usually a pain to but didnt realize they where reps (made in china) does anyone have experience with these? When did your stocks go out?

 

Since you don't state WHICH sensors I'll presume you mean 2 cams and 1 crank. General opinion here is oem only, apparently the Nissan electronics are finicky. My sensors are all original at 108K with 0 problems. OEMs I believe are Hitachi or mb Denso (fka Nippondenso).
Since you've spent the money I'd do this-
See what happens with the ones the motor came with. If codes or no start then
Put in generics as needed. If codes or no start then
Get OEMs from a respectable source.
gl!

 

Thanks for the input

 

Since you are swapping engines, if needed use the sensors off the original engine if needed. When i swapped my engine recently 1 sensor on the donor engine was broken and use my original to replace it with.