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.

 

Pull codes. If its a misfire, it will show a P030x code, then go from there.