Hey I’ve been having a problem with my 2013 Infiniti G37 journey sedan it’s an automatic. Whenever I drive it I notice a jerk or lack of power when it shifts between rpms no check engine light or warning lights pop out on my dash board and I’ve taken it to two mechanics and they’ve said nothings wrong with it. I’ve also noticed when I drive in high speeds on the freeway a whistle noise coming from the engine bay. Recently when I start the car it turns off on its own right away but I try turning it on again and it starts fine. What could it be?
Have you checked the vacuum leak?
Pressure test your fuel pump & check for vacuum leaks - https://youtu.be/oBo-vmEEwv4
Exhaust leak causing oxygen sensors to mis-read and altering fuel/air ratio.
This is an issue with the Firmware or software update. I'm not exactly sure with your model but id research and see if you can find any TSB or ISB for that year before you take it in to have it updated
If you have sport drive in ds or manual and you should notice a difference.