Hey all,
This is a long shot and I've been searching all over but cannot confirm.

My friends 2003 350z engine blew and I swapped the engine over from a JDM 350z engine that my friend purchased. The swap was straight forward minus a few things that had to figure out along the way.

Anyway the car has an Injen True Dual Exhaust and I am getting a P0300 code. On the exhaust side, I am getting sputtering on the passenger side of the exhaust when the driver side is fine.

Things I have changed so far.
-Spark Plugs are new.
-Coil Packs are old and new. I have coil packs from 2 engines that I have been rotating to see if any of them are bad. It seems like the problem is still on the passenger side
-Injector are old and new. Same thing, 2 sets of injectors that I've been rotating
-Intake and TB has been cleaned over and over
-MAF sensor is brand new
-Compression test comes in at 210 per cylinder on passenger side


Car idles fine, and there is no clear misfire yet when i drive, we can get above 3000 rpms but just bogs down even if you floor it. It is a JDM engine and a friend told me that sometimes the JDM engine timing is different from USDM so unless we get it tuned properly or to fire properly we are gonna continue to get this code. Does anyone have any experience on this