I just switched from the jb+ to NM tune to see if I could up the boost. My car has been limited to about 9.5 psi boost since moving back to California regardless of the tune. I am using Torque Pro on my phone to monitor various levels.

My problem is the car feels fast but boost is only coming in between 8-9.5 psi. I pretty much disconnected everything to look for a boost leak and didn't find anything. The turbo doesn't have any play and appears fine. I also noticed that I no longer hear "pops and bangs" when I lift throttle like I used to. Maybe its just me but I love hearing it pop when I down shift of lift the throttle. It gives the car some personality.

What would cause the lack of back fires and somewhat lower boost?