i just bought this 06 350z and it has a really rough misfire. it has an engine swap and supposedly only has 57k miles on it sense the rebuild. i checked the spark plug and they’re pretty old but not bad. the car is running really rich so i think it’s the fuel injectors or timing is off? i’m not sure if the engine is an DE or HR cause it is an engine swap. once i put the spark plugs in the car is now in limp mode so after school ima check the codes with my cbd2.

 

I’m going to bet you got coil pack wires crossed